A rare case of congenital vesico-uterine fistula

Herein we report the case of a patient with primary amenorrhea and cyclical menouria. The patient was a 20 years female with primary amenorrhea. Clinical examination revealed normal external genitilia. A mature female pubic hair pattern was present, and axillary development was normal. Breast was normally developed. Intraoperatively, a congenital vesico-uterine fistulous tract was observed. Repair was done. The patient has been regularly menstruating since the operation

Spontaneous uterine rupture in first trimester of pregnancy

This is a case of 30 years old female who presented in emergency at 11 weeks 3 days with acute abdomen and diagnosed as spontaneous uterine rupture. The defect was repaired and bilateral tubal ligation was done. This shows that uterine rupture can occur as early as that late first trimester and should be included in the differential diagnoses of acute abdomen

Fracture in Phenolic Impregnated Carbon Ablator

The thermal protection materials used for spacecraft heat shields are subjected to various thermal-mechanical loads during an atmospheric entry which can threaten the structural integrity of the system. This paper discusses the development of a novel technique to understand the failure mechanisms inside thermal protection materials. The focus of research is Phenolic Impregnated Carbon Ablator (PICA). It has successfully flown on the Stardust spacecraft and is the TPS material chosen for the Mars Science Laboratory (MSL) and Dragon spacecraft. Although PICA has good thermal properties, structurally, it is a weak material. In order to thoroughly understand failure in PICA, fracture tests were performed on FiberForm* (precursor of PICA), virgin and charred PICA materials. Several samples of these materials were tested to investigate failure mechanisms at a microstructural scale. Stress-strain data were obtained simultaneously to estimate the fracture toughness. It was found that cracks initiated and grew in the FiberForm when a critical stress limit was reached such that the carbon fibers separated from the binder. However, both for virgin and charred PICA, crack initiation and growth occurred in the matrix (phenolic) phase. Both virgin and charred PICA showed greater strength values compared to FiberForm coupons, confirming that the presence of the porous matrix helps in absorbing the fracture energy

Characterizing Novel Circadian Clock Functions for Drosophila Phosphatases and Non-clock Functions for Circadian Photoreceptors

Circadian (~24 h) clocks regulate daily cycles in gene expression to control overt rhythms in physiology, metabolism and behavior. In Drosophila, a transcriptional feedback loop activated by CLOCK-CYCLE (CLK-CYC) complexes, repressed by PERIOD-TIMELESS (PER-TIM) complexes, and synchronized to light: dark cycles primarily by CRYPTOCHROME (CRY), keeps circadian time. The timing of activation and repression is regulated post-translationally, in part through rhythmic phosphorylation of CLK, PER, and TIM. Although kinases that control CLK, PER, and TIM levels, activity, and/or subcellular localization have been identified, less is known about phosphatases that control clock protein dephosphorylation. Using genetic, behavioral and molecular analyses, I identified protein phosphatases that function within the Drosophila circadian clock. Moreover, I took advantage of behavioral, molecular, and electrophysiological analyses to characterize CRY expression and function in peripheral tissues of Drosophila melanogaster. To identify phosphatases, clock cell-specific RNAi knockdowns of all annotated phosphatases in Drosophila were screened for altered activity rhythms. I identified 22 such phosphatases that either lengthened or shortened circadian period by ≥ 1 h or were significantly arrhythmic. The efficacy and specificity of RNAis was validated by testing RNAis that targeted other regions of the mRNA, transposon inserts, and either existing or CRISPR-generated loss of function mutants for defects in activity rhythms. One phosphatase identified, Leukocyte-Antigen-Related (LAR), regulates the development of neuronal circuit underlying the communication between clock neurons in the fly brain. This work, along with the analysis of another 15 candidates that remain after validation, will reveal novel features of the circadian timekeeping mechanism in Drosophila that may be conserved in all animals including humans. Furthermore, using a GFP-tagged-cry transgene, I show that CRY is expressed in Drosophila peripheral tissues and promotes light-dependent TIM degradation. Electrophysiological recordings from larval salivary glands which lack a circadian clock and are non-excitable, demonstrated that CRY regulates cell membrane physiology in collaboration with K+ channels. These findings for the first time define the expression profile of CRY in Drosophila peripheral tissues, and reveal that CRY functions in a light-independent and K+ channel-dependent manner to alter membrane function in peripheral tissues devoid of a canonical circadian clock

Thermal Analysis of Small Re-Entry Probe

The Small Probe Reentry Investigation for TPS Engineering (SPRITE) concept was developed at NASA Ames Research Center to facilitate arc-jet testing of a fully instrumented prototype probe at flight scale. Besides demonstrating the feasibility of testing a flight-scale model and the capability of an on-board data acquisition system, another objective for this project was to investigate the capability of simulation tools to predict thermal environments of the probe/test article and its interior. This paper focuses on finite-element thermal analyses of the SPRITE probe during the arcjet tests. Several iterations were performed during the early design phase to provide critical design parameters and guidelines for testing. The thermal effects of ablation and pyrolysis were incorporated into the final higher-fidelity modeling approach by coupling the finite-element analyses with a two-dimensional thermal protection materials response code. Model predictions show good agreement with thermocouple data obtained during the arcjet test

Fracture in Phenolic Impregnated Carbon Ablator

This paper describes the development of a novel technique to understand the failure mechanisms inside thermal protection materials. The focus of this research is on the class of materials known as phenolic impregnated carbon ablators. It has successfully flown on the Stardust spacecraft and is the thermal protection system material chosen for the Mars Science Laboratory and SpaceX Dragon spacecraft. Although it has good thermal properties, structurally, it is a weak material. To understand failure mechanisms in carbon ablators, fracture tests were performed on FiberForm(Registered TradeMark) (precursor), virgin, and charred ablator materials. Several samples of these materials were tested to investigate failure mechanisms at a microstructural scale. Stress-strain data were obtained simultaneously to estimate the tensile strength and toughness. It was observed that cracks initiated and grew in the FiberForm when a critical stress limit was reached such that the carbon fibers separated from the binder. However, both for virgin and charred carbon ablators, crack initiation and growth occurred in the matrix (phenolic) phase. Both virgin and charred carbon ablators showed greater strength values compared with FiberForm samples, confirming that the presence of the porous matrix helps in absorbing the fracture energy

Arcjet Testing of Micro-Meteoroid Impacted Thermal Protection Materials

There are several harsh space environments that could affect thermal protection systems and in turn pose risks to the atmospheric entry vehicles. These environments include micrometeoroid impact, extreme cold temperatures, and ionizing radiation during deep space cruise, all followed by atmospheric entry heating. To mitigate these risks, different thermal protection material samples were subjected to multiple tests, including hyper velocity impact, cold soak, irradiation, and arcjet testing, at various NASA facilities that simulated these environments. The materials included a variety of honeycomb packed ablative materials as well as carbon-based non-ablative thermal protection systems. The present paper describes the results of the multiple test campaign with a focus on arcjet testing of thermal protection materials. The tests showed promising results for ablative materials. However, the carbon-based non-ablative system presented some concerns regarding the potential risks to an entry vehicle. This study provides valuable information regarding the capability of various thermal protection materials to withstand harsh space environments, which is critical to sample return and planetary entry missions

Thermal Testing of Thermal Protection System (TPS) Materials

High temperature testing of thermal protection system (TPS) materials is a critical aspect of heat-shield materials development, as it determines the suitability and performance envelope of the materials. The present talk provides an overview of different high temperature test facilities that are available for conducting thermal tests for TPS materials. The facilities include arcjet testing, solar tower testing facilities and laser test facility. The facilities are selected based on the requirements and objectives of the tests and each have their benefits and limitations. The paper also describes the process of determining the test environments based on mission profiles and requirements. Some of the recent thermal tests of TPS materials are discussed in this paper. These tests have helped improve the TRL (Technology Readiness Level) level of novel TPS materials and make them viable TPS material candidates for future missions

Investigation of Performance Envelope for Phenolic Impregnated Carbon Ablator (PICA)

The present work provides the results of a short exploratory study on the performance of Phenolic Impregnated Carbon Ablator, or PICA, at high heat flux and pressure in an arcjet facility at NASA Ames Research Center. The primary objective of the study was to explore the thermal response of PICA at cold-wall heat fluxes well in excess of 1500 W/cm (exp 2). Based on the results of a series of flow simulations, multiple PICA samples were tested at an estimated cold wall heat flux and stagnation pressure of 1800 W/cm (exp 2) and 130 kPa, respectively. All samples survived the test, and no failure was observed either during or after the exposure. The results indicate that PICA has a potential to perform well at environments with significantly higher heat flux and pressure than it has currently been flown

Work related musculoskeletal disorders among medical laboratory professionals: a narrative review

Work related musculoskeletal disorders are common health problem and increasing cause of disability. Laboratory professionals are unique group of healthcare professionals who play an essential part in diagnosis and therapy planning and often their work is associated with potential health hazards. Objective of current study was to review literature on prevalence of work-related musculoskeletal disorders among medical laboratory professionals. Electronic databases and bibliographies were searched and identified papers evaluated against inclusion criteria. The searching strategy uncovered 13 reports. Total 7 studies were included for the review. A high degree of heterogeneity among studies was observed. The overall prevalence’s ranges from 40-60%. With neck being more prevalent 18-78%. However additional high quality studies are required in this area