INTRODUCTION: The use of glass ionomer cements (GIC) as a restorative material was limited to areas of low masticatory forces due to their low mechanical properties which were also affected by the powder/liquid mixing ratio of this material. Bond strength is important for the clinical success of adhesive material. The shear bond strength (SBS) is the maximum force that an adhesive joint can tolerate before fracture which is tested by SBS tests. The high bond strength helps the adhesive to resist stresses caused by resin contraction and forces for a longer time and thus prevents the problems of bond failure such as recurrent caries, tooth sensitivity and restoration failure. GIC as a restorative material has the capacity to release fluoride and shows good bonding ability. The use of GIC in anterior applications appears to be satisfactory, but they have limitations for use in permanent posterior teeth, particularly with regard to large restorations. Zirconia-reinforced GI (Zirconomer, Shofu Inc, Japan) is a new class of restorative material containing reinforced glass ionomer with special zirconia fillers that promises the strength and durability of amalgam with the protective benefits of glass ionomer while eliminating the hazards of mercury. Amalgomer CR (Advanced Health Care, Tonbridge, Kent, UK), a novel ceramic-reinforced GIC, was introduced, which combines the benefits of GIC with the high strength of ceramics. In the present study, shear bond strength to the dentin with Zirconomer, Amalgomer CR and Fuji type IX GIC (GC Tokyo) are compared. AIM: To evaluate the shear bond strength of three different aesthetic materials to dentin. METHODOLOGY: Thirty extracted human molar teeth were taken, cleaned, stored and the occlusal surfaces of the teeth were flattened with a straight fissured bur at a depth of three millimetres until dentin was exposed. Acrylic blocks were prepared by cold cure acrylic resin and the samples were embedded into the blocks and conditioning of dentin was done using dentin conditioner (GC Corporation Tokyo, Japan). Out of 30 dentin-exposed samples, 10 samples were restored with Zirconomer, the other 10 with Amalgomer CR and the remaining 10 with GIC respectively. All the specimens were transferred to the universal testing machine individually and subjected to shear bond strength analysis. RESULT: Statistical analysis was done for all three groups by using descriptive statistics that include one-way ANOVA and Tukey's multiple post hoc procedures for intergroup comparison. CONCLUSION: Zirconomer showed better shear bond strength than Amalgomer CR and GIC

Abstract Introduction Temporomandibular joint disorders (TMD) present with a multitude of symptoms that can range from headaches to shoulder pain. Patients frequently present with pain in the ear, dizziness, and vertigo. It is noted that some patients who report TMDs also have a history of sleep disturbances, which is noted in cone beam computed tomography (CBCT) as a reduction in the oropharyngeal airway volume. Objective To evaluate the airway volume in pre- and posttreatment of TMD with the use of neuromuscular orthotics made with ultra-low frequency transcutaneous electrical nerve stimulation (ULF-TENS). Methods A total of 15 patients were evaluated for TMDs using the related criteria. Those included were treated with ULF-TENS with evaluation of the airway volume both pre- and posttreatment using CBCT and the Dolphin 3D volume analysis software. Results While the symptoms were shown to be significantly reduced in patients who were treated with this particular modality, the airway volume varied in those who reported a reduction after a period of 3 months and those that reported after a period of 6 months. Conclusion Posttreatment evaluation of the airway should be done after a period of 6 months for a more objective evaluation. A multidisciplinary evaluation of the patient is required in such cases.

ABSTRACT Background: Methicillin resistance and biofilm-producing Staphylococci are emerging as multidrug-resistant strains narrowing the efficacy of antimicrobial therapy. Although vancomycin is used as the drug of choice to treat such isolates, different studies worldwide have documented the emergence of strains that are intermediately susceptible or resistant to this antibiotic. Objective: The study aimed to determine the minimum inhibitory concentration of vancomycin to methicillin-resistant and biofilm-producing staphylococci isolated from different clinical specimens. Methods: 375 staphylococci isolated from different clinical specimens over one year were included in the study. Biofilm formation was determined by the Tissue culture plate method (TCP), and ica genes were identified by Polymerase Chain Reaction (PCR). Antibiotic susceptibility and methicillin resistance were done following Clinical and Laboratory Standards Institute (CLSI) guidelines. The minimum inhibitory concentration (MIC) of vancomycin in all isolates was determined by the agar dilution method. Results: Among 375 Staphylococci studied, 43% and 57% represented S. aureus and Coagulase- Negative Staphylococci (CNS), respectively. The rate of Methicillin-Resistant S. aureus (MRSA) and Methicillin-Resistant Coagulase Negative Staphylococci (MRCNS) were 81.4% and 66.8% respectively and determined by the disc diffusion method. The most potential antibiotics were tetracycline and chloramphenicol showing sensitivity to more than 90% isolates. The Minimum Inhibitory Concentration (MIC) value of oxacillin for staphylococci ranged from 0.125-32 μg/ml. Oxacillin agar diffusion method showed 51.6% and 79.9% isolates as MRSA and MRCNS, respectively, revealing a very high percentage of S. aureus and CNS isolates as methicillin-resistant. All isolates had susceptible vancomycin MICs that ranged from 0.125-2 μg/ml. Two S. aureus isolated from Central Venous Catheter (CVC) and catheter specimens were detected with intermediate susceptibility to vancomycin. Similarly, three CNS isolated from blood, CVC, and wound/pus (w/p) were intermediately susceptible to vancomycin. Strong biofilm formation was observed in 22.1% of clinical isolates, and the ica gene was detected among 22.9% of isolates. Only one S. aureus detected as a biofilm producer by the TCP method was found to have intermediate susceptibility to vancomycin. Conclusions: The increment in vancomycin MIC among methicillin-resistant and biofilm-producing staphylococci is alarming. Strict control measures to prevent methicillin-resistant isolates spread and routine surveillance for vancomycin-resistant isolates must be incorporated in hospitals to prevent antimicrobial treatment failure.

RESUMEN Antecedentes: Los estafilococos resistentes a la meticilina y productores de biopelículas están surgiendo como cepas multirresistentes que reducen la eficacia del tratamiento antimicrobiano. Aunque la vancomicina se utiliza como fármaco de elección para tratar dichos aislados, diferentes estudios realizados en todo el mundo han documentado la aparición de cepas intermedias susceptibles o resistentes a este antibiótico. Objetivo: El estudio tenía como objetivo determinar la concentración mínima inhibitoria de la vancomicina para los estafilococos resistentes a la meticilina y productores de biofilm aislados de diferentes muestras clínicas. Métodos: Se incluyeron en el estudio 375 estafilococos aislados de diferentes muestras clínicas durante un año. La formación de biopelículas se determinó mediante el método de la placa de cultivo de tejidos (TCP), y los genes ica se identificaron mediante la reacción en cadena de la polimerasa (PCR). La susceptibilidad a los antibióticos y la resistencia a la meticilina se realizaron siguiendo las directrices del Clinical and Laboratory Standards Institute (CLSI). La concentración inhibitoria mínima (MIC) de vancomicina en todos los aislados se determinó por el método de dilución en agar. Resultados: Entre los 375 estafilococos estudiados, el 43% y el 57% representaban S. aureus y estafilococos coagulasa-negativos (ECN), respectivamente. La tasa de S. aureus resistente a la meticilina (SARM) y de estafilococos coagulasa negativos resistentes a la meticilina (ECNM) fue del 81,4% y el 66,8%, respectivamente, y se determinó por el método de difusión de discos. Los antibióticos más potenciales fueron la tetraciclina y el cloranfenicol, que mostraron una sensibilidad superior al 90% de los aislados. El valor de la concentración inhibitoria mínima (CIM) de la oxacilina para los estafilococos osciló entre 0,125-32 μg/ml. El método de difusión en agar de la oxacilina mostró que el 51,6% y el 79,9% de los aislados eran SARM y MRCNS, respectivamente, lo que revela que un porcentaje muy elevado de los aislados de S. aureus y CNS son resistentes a la meticilina. Todos los aislados tenían MIC de vancomicina susceptibles que oscilaban entre 0,125-2 μg/ml. Se detectaron dos S. aureus aislados de muestras de catéteres venosos centrales (CVC) y catéteres con una susceptibilidad intermedia a la vancomicina. Del mismo modo, tres S. aureus aislados de sangre, CVC y herida/pus (w/p) fueron intermedianamente susceptibles a la vancomicina. Se observó una fuerte formación de biopelículas en el 22,1% de los aislados clínicos, y se detectó el gen ica en el 22,9% de los aislados. Sólo un S. aureus detectado como productor de biopelículas por el método TCP resultó tener una susceptibilidad intermedia a la vancomicina. Conclusiones: El incremento de la MIC de vancomicina entre los estafilococos resistentes a la meticilina y productores de biofilm es alarmante. Para evitar el fracaso del tratamiento antimicrobiano, deben incorporarse en los hospitales medidas de control estrictas para prevenir la propagación de los aislados resistentes a la meticilina y una vigilancia rutinaria de los aislados resistentes a la vancomicina.

Utilizing biomaterials for every conceivable purpose area, such as automobiles, sporting goods, medical, civil, and textile industries, is the aim of the research field. Applications of Natural Fiber (NF) reinforced polymer composites in structural and tribological engineering are rapidly expanding. For the first time in this work, Prosopis juliflora bark and two different types of NF (jute and kenaf) were reinforced with polyester matrix by the hand layup method. The objective of the work is to determine the wear performance and viscoelastic properties of the new hybrid bio-composite. Under dry contact conditions, the tribological performance of the proposed hybrid composite material was evaluated using a range of process parameters, including sliding distance (1000-2000 m), applied load (10-50 N), and sliding velocity (1-5 m/s). The wear behaviour of the fabricated NF composite was greatly enhanced (17.5 x10-8 mm3 /N-mm) by the higher composition of kenaf fibers has been observed. The dynamic mechanical analysis (DMA) showed that the manufactured composites had high storage modulus (4.1 GPa) and loss modulus (3.8 GPA). SEM was used to investigate and propose a potential wear mechanism for the developed composites by evaluating the exterior geomorphology of samples after wear tests. AFM provided details on the fiber surface properties of hybrid composites.

RESUMO: A partir de um caso de intoxicação iatrogênica por selenito de sódio injetável em suíno verificaram-se alguns aspectos patogenéticos não esclarecidos, o que ensejou o estudo experimental. Selenito de sódio foi administrado pelas vias oral e parenteral a 13 suínos, subdivididos em três grupos (G1, G2 e G3). Os grupos G1 e G3 receberam selenito de sódio por via intra-muscular (IM); (G1 - fórmula comercial e G3 - selenito de sódio misturado à água destilada, em diversas dosagens) e o grupo G2, por via oral (VO), misturado à ração. Quadros de evolução aguda e subaguda foram observados em todos os grupos, embora o início dos sintomas tenha sido mais lento no grupo G2. Um único porco (do grupo G1), que havia recebido a dose mais alta, apresentou evolução superaguda. Apatia, anorexia, dispneia, vômito, tremores musculares, déficit proprioceptivo, ataxia e paresia dos membros posteriores com progressão para os anteriores e evolução para tetraplegia foram observados. Os achados de necropsia foram diferentes entre os animais que receberam o selenito de sódio injetável (IM - G1 e G3) e oral (G2). Havia moderada atrofia hepática em alguns animais do G2. Parte dos animais dos grupos G1 e G3 apresentaram edema pulmonar. Em um suíno (G3) notaram-se áreas marrom-amareladas nos cornos ventrais da intumescência cervical. As alterações histológicas mais importantes ocorreram nos cornos ventrais do “H” medular das intumescências cervical e lombar. Em um animal, as alterações envolviam o tronco cerebral e o mesencéfalo. Inicialmente, a lesão caracterizava-se por edema perivascular e astrocitário que progredia para lise e necrose de astrócitos e neurônios. O estágio crônico das lesões caracterizava-se por extensas áreas de necrose liquefativa e infiltração perivascular linfocítica e histiocítica, com raros eosinófilos. Sugere-se que a ruptura da barreira hematoencefálica por edema astrocitário seja o mecanismo mais provável da lesão no SNC.

ABSTRACT: Following a case of iatrogenic selenium poisoning in a young pig, an experimental study was carry out. Sodium selenite was orally and parenterally administered to 13 pigs that were subdivided into three groups (G1, G2 and G3). The animals in groups G1 and G3 received sodium selenite intramuscularly (IM), G1 received a comercial formula, and G3 received sodium selenite mixed with distilled water at different dosages, and those in group G2 were fed commercial sodium selenite. Acute and subacute poisoning was observed in both groups, although the onset of clinical signs was slower in group G2. Only one pig (in group G1) that had received the highest dose showed a peracute course. Apathy, anorexia, dyspnea, vomiting, muscular tremors, proprioceptive deficit, ataxia and paresis of the hind limbs progressing to the front limbs evolving to tetraplegia were observed. Postmortem findings differed whether the animals received the injected (G1 and G3) or oral (G2) sodium selenite. The liver was moderately atrophic in some animals of G2. Some of the animals in groups G1 and G3 presented with lung edema. One pig in G3 had yellowish-brown areas in the ventral horns of the cervical intumescences of the spinal cord. The most important histological changes were present in the ventral horns of the cervical and lumbar intumescences of the spinal cord. In one animal, changes were present in the brainstem and mesencephalon. The initial lesion was a perivascular and astrocyte edema that progressing to lysis and death of astrocytes and neurons. In the chronic stage of the lesions, there were extensive areas of liquefaction necrosis with perivascular lymphocytic and histiocytic infiltration and occasional eosinophils. It seems that disruption of the blood-brain barrier due to astrocyte edema is the most likely mechanism of CNS lesion.

Pentadentate Schiff base ligand(N,N-bis(2-hydroxy-1-naphthylidene) diethylenetriamine) (H2L) that exhibits a N3O2 donor set. Five rare earth complexes lanthanide (III), praseodymium (III), neodymium(III), samarium(III)and europium (III) complexes are synthesized and characterized based on elemental analyses, molar conductance, infrared, ultraviolet, thermo gravimetric, X-ray powder diffraction and mass spectral studies. Molar conductivity data suggests that the complexes are 1:1 electrolytics. Infrared spectral data suggest that the ligand binds through two naptholic oxygen atoms, two azomethine nitrogen atoms and one primary amine. IR studies reveal that the complexes contain both coordinating and ionic nitrate ligands. Thermal decomposition studies indicate the presence of two nitrate ions and two water molecules in the inner coordination sphere. Eu3+ and Sm3+ complexes exhibit luminescence properties. Further, the binding properties of these complexes with calf-thymus DNA have been investigated using absorption spectrophotometry.

ABSTRACT The actinobacterial strain Streptomyces lavendulocolor VHB-9 was isolated from granite mine soil samples of Khammam district, Telangana state, India. The strain was identified based on detailed microorphological, cultural and phylogenetic analysis. Bioactive guided isolation of the secondary metabolites of the strain was carried out by growing the strain in optimized medium (0.5% lactose, 0.5% peptone, 0.05% K2HPO4, 0.2% CaCO3 with pH adjusted to 7.0). Separation and purification of the active fractions from the crude ethyl acetate extract was carried out by silica gel column chromatography and resulted in the isolation of two active fractions. Structural elucidation of the two (B2 and B3) active compounds was carried out by FT-IR, Mass and NMR spectroscopy and were identified as Bis (7-methyloctyl) phthalate and (Z)-3-aminoacrylic acid. The antimicrobial activity of the bioactive compounds produced by S. lavendulocolor VHB-9 was expressed in terms of minimum inhibitory concentration against opportunistic pathogenic bacteria and fungi. Both fractions exhibited good antimicrobial potential against the bacteria and fungi tested.

ABSTRACT Purpose To compare the efficacy of percutaneous nephrolithotomy (PCNL) as a primary procedure of patients following previous open surgery or post percutaneous nephrolithotomy (PCNL) for renal calculi. Materials and Methods The medical records of 367 patients who underwent PCNL by a single surgeon from January 2008 to December 2013 were reviewed retrospectively. All patients were divided into 3 Groups. Group-1 (n=232) included patients with no history of ipsilateral open stone surgery. Group 2 (n=86) patients had undergone one or more open stone surgeries before PCNL, patients with failed or recurrence following PCNL were placed in Group-3 (n=49). The demographic data, operation duration, stone free rate (SFR), number of attempts to access the collecting system and intra operative and postoperative complications between the three Groups were compared. Results There was no difference in sex, Body Mass Index (BMI), stone burden and laterality among the three Groups. Operation time was significantly less in first Group, while there was a statistically significant difference in operation duration between second and third Groups (p<0.05). The number of attempts to enter the collecting system was lower in the first Group in comparison to other two Groups (p<0.5). There was no significant differences among three groups in stone free rate. Intra operative and postoperative complications were slightly more frequent in Groups 2 and 3. Mortality occurred in 1 patient with colon perforation in Group-2. Conclusion Our study demonstrated that PCNL can be performed in patients even as secondary procedure without further complications.

Mesoscale atmospheric circulations play an important role in the transport of air pollution and local air quality issues. The planetary boundary layer (PBL), the thermo-dynamical structure and the flow field play an important role in air pollution dispersion. Hence, the PBL parameters over Nagpur, India are simulated using the ARW v. 3.6.1 mesoscale model. High-resolution simulations are conducted with triple nested domains having a horizontal resolution of 27, 9 and 3 km, as well as 27 vertical levels by using the 1 x 1° NCEP Final Analysis meteorological fields for initial and boundary conditions. Eight fair-weather days in winter and summer (January and April 2009) with no significant synoptic activity were chosen for the study. Sensitivity experiments of the ARW model were conducted with two non-local (Yonsei University [YSU], and Asymmetric Convective Model v. 2 [ACM2]) and three local turbulence kinetic energy (TKE) closure (Mellor-Yamada Nakanishi and Niino Level 2.5 PBL [MYNN2], Mellor-Yamada-Janjic [MYJ], and quasi-normal scale elimination [QNSE]) turbulence diffusion parameterizations, to study the evolution of PBL parameters and the thermodynamical structure during the study period. After validation of the simulated parameters with the available in situ data, it was revealed that the non-local PBL scheme YSU, followed by local scheme MYNN2, could be able to capture the characteristic variations of surface meteorological variables and the thermodynamical structure of the atmosphere. The present results suggest that PBL schemes, namely YSU and MYNN2, performed better in representing the boundary-layer parameters and are useful for air pollution dispersion studies.

Las circulaciones atmosféricas de mesoescala desempeñan un papel importante en el transporte de la contaminación del aire y en cuestiones relacionadas con la calidad del aire a nivel local. La estructura termodinámica de la capa limítrofe planetaria (PBL, por sus siglas en inglés) y el campo de flujo también desempeñan un papel importante en la dispersión de contaminantes en la atmósfera. Por lo tanto, se simularon los parámetros de la PBL sobre Naigpur, India, utilizando el modelo de mesoescala ARW v. 3.6.1. Las simulaciones de alta resolución se llevaron a cabo por medio de dominios anidados con resolución horizontal de 27, 9 y 3 km, y 27 niveles verticales obtenidos mediante la utilización de los campos meteorológicos de 1 x 1° del análisis final del NCEP, para las condiciones iniciales y limítrofes. Para estudiar la evolución de los parámetros de la PBL y la estructura termodinámica durante el periodo de estudio, se eligieron ocho días de invierno y verano (enero y abril) con buen tiempo y ausencia de actividad sinóptica significativa. Se realizaron experimentos de sensibilidad del modelo ARW con dos parametrizaciones de la difusión turbulenta del cierre de energía cinética (TKE, por sus siglas en inglés) no locales (Yonsei University [YSU] y el Modelo Convectivo Asimétrico v. 2 [ACM2, por sus siglas en inglés]) y tres locales (Mellor-Yamada-Nakanishi and Niino Level 2.5 PBL [MYNN2], Mellor-Yamada-Janjic [MYJ] y eliminación de escala casi normal [QNSE, por sus siglas en inglés]). La validación de los parámetros simulados mediante el modelo con los datos in situ disponibles reveló que el esquema PBL no local YSU seguido del esquema local MYNN2 podrían reproducir las variables meteorológicas superficiales y la estructura termodinámica de la atmósfera. Los resultados del estudio sugieren que los esquemas PBL, en especial YSU y MYNN2, tuvieron un mejor desempeño para representar los parámetros de la capa limítrofe y son útiles en estudios de dispersión de contaminantes atmosféricos.

In this study seismic noise records from the permanent broadband network of the Mexican National Seismological Service (Servicio Sismológico Nacional) and from the temporal broadband networks of MASE and VEOX have been used to compute the Green functions from vertical-vertical component of noise cross correlations between station pairs. MASE (Mesoamerican Seismic Experiment) consisted of one hundred stations deployed along a profile perpendicular to the trench from Acapulco, Guerrero, to Tempoal, Veracruz, Gulf of Mexico. This experiment was carried out from December 2004 to May 2007. Forty six of these stations were relocated along a N-S profile crossing the Tehuantepec Isthmus from the Gulf of Mexico to the Pacific coast. These stations operated from July 2007 to March 2009 and this stage of the experiment was called VEOX (Veracruz-Oaxaca). From the Green functions extracted from the correlation for each pair of stations, Rayleigh wave dispersion curves were computed which represent the average group velocity between station pairs. Furthermore, regional earthquakes recorded by the stations were used in order to compute Rayleigh wave dispersion curves, which represent the average group velocity between epicenter-station pair. This mixed set of group velocity measurements was inverted to obtain tomographic images at discrete periods between 5 and 50 s. Resolution tests show that the regions of best coverage surround both temporal experiments. A good velocity model was obtained in a large area between the two experiments. The images show good correlation at short periods (< 15 s) with the shallowest geological features. Low velocity anomalies are related with sedimentary basins and Cenozoic volcanic areas, whereas high velocity anomalies correlate with the forearc region. A low-velocity anomaly was clearly observed at the north of the Isthmus of Tehuantepec where an active volcanic field is located. At larger periods (> 25 s) a low velocity region coincides with the border of the Trans- Mexican Volcanic Belt, suggesting the presence of a mantle wedge. For these periods, high velocity anomalies are related with the shallow presence of the oceanic mantle in the forearc and the presence a shallower mantle in the backarc, where the continental crust becomes thin.

En este trabajo se utilizaron registros de ruido sísmico de la red permanente de banda ancha del Servicio Sismológico Nacional de México y de las redes temporales de banda ancha MASE y VEOX para calcular las funciones de Green a partir de las correlaciones cruzadas de ruido de la componente vertical entre pares de estaciones. El arreglo MASE (Experimento de Subducción Mesoamericano) consistió en cien estaciones distribuidas a lo largo de un perfil perpendicular a la trinchera entre Acapulco, Guerrero, y Tempoal, Veracruz, cerca del Golfo de México. Este experimento operó de diciembre de 2004 a mayo de 2007. Cuarenta y seis de éstas estaciones se reubicaron en un perfil N-S va desde el Golfo de México hasta la costa del Pacífico, a través del Istmo de Tehuantepec. Este segundo arreglo de estaciones corrió de julio de 2007 a marzo de 2009 y se le denominó VEOX (Veracruz-Oaxaca). A partir de la función de Green extraída de la correlación cruzada entre cada par de estaciones, se obtuvieron las curvas de dispersión de ondas de Rayleigh, las cuales describen la velocidad de grupo promedio dentro de un intervalo de periodos determinado. Además, se utilizaron algunos sismos regionales registrados en estas redes sísmicas para obtener curvas de dispersión de ondas superficiales (Rayleigh) y, en consecuencia, la velocidad de grupo promedio entre cada par estación-epicentro. Este conjunto mezclado de mediciones de velocidad de grupo se invirtió para obtener imágenes tomográficas en periodos discretos (5-50 s). Las pruebas de resolución muestran que las regiones con mayor cobertura están en los alrededores de ambos experimentos temporales. Se obtiene un buen modelo de velocidad en un área grande entre ambos experimentos. En los periodos cortos (< 15 s), las imágenes presentan buena correlación con las características geológicas superficiales. Las anomalías de baja velocidad están relacionadas con cuencas sedimentarias y áreas volcánicas del Cenozoico, mientras que las anomalías de altas velocidades se correlacionan con la región del antearco. Se observa una anomalía de baja velocidad muy clara al norte del Istmo de Tehuantepec, donde se encuentra un campo volcánico activo. En los periodos más grandes (> 25 s), una anomalía de baja velocidad coincide con la frontera de la Faja Volcánica Transmexicana, lo que sugiere la presencia de una cuña del manto. Para estos periodos, las anomalías de alta velocidad están relacionadas con la presencia superficial del manto oceánico en el antearco y de un manto menos profundo en el trasarco donde la corteza continental se adelgaza.

Resumo: Este trabalho apresenta as atividades na área de propulsão líquida no IAE, que teve um impulso efetivo no final da década de 90. É consenso entre os especialistas da área espacial a utilização da tecnologia de propulsão líquida nas futuras gerações de veículos lançadores de satélites, com o objetivo de elevar significativamente o desempenho do foguete e a precisão de inserção de satélites. Diversas atividades nesta área encontram-se em desenvolvimento, entre as quais podem ser citadas: os motores L5, L15 e L75, as especificações das instalações de testes de motores, componentes e estágios de foguetes, além de um programa de capacitação de recursos humanos nas áreas de projeto, fabricação e testes de motores foguetes desta natureza.

Abstract: This paper presents the activities in the area of liquid propulsion, which received an effective boost at the end of the 90s. There is a consensus among specialists on the use of liquid propulsion in the next generation of satellite launcher vehicles in order to increase significantly both the performance and the satellites insertion accuracy. Several activities in this area are in development, among which should mention, the L5, the L15 and the L75 LPRE, the specifications for engine testing facilities for components and rocket stages, and a human resources program for training in the areas of liquid rocket engine design, manufacture and testing.

Portulaca oleracea Linn, pertence à família Portulaceae e é uma erva daninha amplamente distribuída. Ela tem sido utilizada como remédio popular em muitos países como diurético, febrífugo, anti-séptico, antiespasmódico e vermífugo. Este artigo aborda o estudo microscópico da folha, caule e raiz de Portulaca oleracea, juntamente com as análises físico-química e fitoquímica preliminar que foram também estudadas.

Portulaca oleracea Linn, belongs to family Portulaceae and is a widely distributed weed. It has been used as a folk medicine in many countries as diuretics, febrifuge, antiseptic, antispasmodic and vermifuge. This paper deals with the microscopic study of leaf; stem and root of Portulaca oleracea, along with the physico-chemical and preliminary phytochemical analyses that were also studied.

Coolants are widely used in industries for metal cutting operations. Though there are varieties of coolants available, the most widely used are water-soluble coolants because of their low cost and better heat dissipation compared to straight cutting oils. In the present investigation, amongst the various causes, which deteriorate the coolant, the role of hardness of water is primarily studied. Accordingly, water from different sources with varying hardness is considered and coolants are prepared from the same. The extent to which hardness can affect the performance of coolants is studied as a function of coolant lubricity in a reciprocating tribometer. Further, the effect of entry of coolants into lubricated machine tool slideways is also assessed by evaluating the mixture of coolant and lubricating oil for its frictional behavior. This is important from assessing the impact of the mixing of coolant and lubricating oil on machine tool slideways with regard to positioning exactness and stick slip behavior of slideways in terms of coolant-lube compatibility.

Emergence of multi and pan-drug resistant Gram-negative bacteria causing nosocomial infections in intensive care settings has become a challenge for clinicians. The mortality rate of ventilator-associated pneumonia (VAP) is known to increase when the initial microbiological diagnosis and antimicrobial therapy are inappropriate. We present a case of a 18-year-old man, who after being admitted following an accident, had developed VAP due to multi-drug resistant Pseudomonas aeruginosa and Acinetobacter spp. and had a downhill clinical course despite broad-spectrum antibiotic treatment. The strains were found to be Col-S, as the susceptibility was tested. Colistin was instituted, with remarkable recovery. It is imperative to diagnose VAP with multi-drug resistant strains as early as possible; colistin, the 'last resort' antibiotic, if instituted with proper monitoring at the right time, can be life saving.

The current study determined the spectrum of biliary microflora with special emphasis on enteric fever organisms in patients with acute cholangitis with and without cholelithiasis or other biliary diseases. The patients were divided into three groups: Group A consisted of patients with acute cholecystitis with cholelithiasis; Group B consisted of patients with acute cholecystitis with gastrointestinal ailments requiring biliary drainage and group C consisted of patients with gallbladder carcinoma. Gallbladder, bile and gallstones were subjected to complete microbiological and histopathological examination. Antimicrobial susceptibility of the isolates was performed as per CLSI guidelines. Bacteria were recovered from 17 samples (32%) in Group A, 17 (51.4%) in Group B and 1 (1.6%) in Group C. The most common organisms isolated were Escherichia coli (11, 29.7%), Klebsiella pneumoniae (10, 27%), Citrobacter freundii (3, 8.1%), Salmonella enterica serovar Typhi (3, 8.1%), etc. The majority of Enterobacteriaceae isolates were susceptible to piperacillin-tazobactam and meropenem. As regards Salmonella spp., S. Typhi was isolated from 2 (3.8%) patients in Group A and 1 (16%) in Group C. Antimicrobial susceptibility of potential causative organisms, the severity of the cholecystitis, and the local susceptibility pattern must be taken into consideration when prescribing drugs. A protocol regarding the management of such cases should be formulated based on observations of similar studies.