Identification of a CD4+ T cell-stimulating antigen of pathogenic bacteria by expression cloning.

Identifying the immunogenic proteins that elicit pathogen-specific T cell responses is key to rational vaccine design. While several approaches have succeeded in identifying major histocompatibility complex (MHC) class I bound peptides that stimulate CD8+ T cells, these approaches have been difficult to extend to peptides presented by MHC class II molecules that stimulate CD4+ T cells. We describe here a novel strategy for identifying CD4+ T cell-stimulating antigen genes. Using Listeria monocytogenes-specific, lacZ-inducible T cells as single-cell probes, we screened a Listeria monocytogenes genomic library as recombinant Escherichia coli that were fed to macrophages. The antigen gene was isolated from the E. coli clone that, when ingested by the macrophages, allowed generation of the appropriate peptide/MHC class II complex and T cell activation. We show that the antigenic peptide is derived from a previously unknown listeria gene product with characteristics of a membrane-bound protein

Silicon saw-tooth refractive lens for high-energy X-rays made using a diamond saw

A Si saw-tooth refractive lens, fabricated by a dicing process, is demonstrated to focus a 115 keV X-ray beam

The role of color Doppler and spectral flow analysis in the management of pregnancy induced hypertension

Background: Nearly one third intrauterine death of normally formed singleton fetuses are associated with IUGR coexisting with or without pregnancy induced hypertension (PIH). Abnormal fetal circulation is considered a major factor in fetal growth restriction, both as a cause and an indicator. Doppler ultrasound is a relatively new technique which merits investigations as a screening method for IUGR and PIH as both are associated with placental vascular pathology. The development of Doppler ultrasonographic technology, particularly during last 10 years, has provided an opportunity to obtain both qualitative and quantitative assessment of maternal and fetal hemodynamics using a non-invasive method. Objectives were to assess the role of color Doppler and spectral flow analysis in the management of pregnancy induced hypertension.Methods: It was a prospective observational study in which 50 pregnant women were taken as cases with pregnancy induced hypertension and 25 as matched controls without any high-risk factor. All patients were examined for colour Doppler spectral flow analysis. Detailed USG results in the form of maturity by biparietal diameter, head circumference, femoral length, abdominal circumference, liquor, and expected fetal weight were measured and noted. Doppler study of umbilical artery, fetal middle cerebral artery, both maternal uterine arteries and ductus venosus was carried out. Parameters in the form of resistive index (RI), pulsatility index (PI) and systolic/diastolic ratio (S/D) of all four arteries were taken. In ductus venosus waveform, changes in the ‘a’ wave were noted. All participants were followed up from the point of the recruitment up to the time of delivery. At the time of delivery, the mode of delivery, any complications, the Apgar score, weight of the baby, birth asphyxia and admission in NICU were noted.Results: The number of patients with PIH were highest in the age group of 21-25 years [n=31 (62%)]. IUGR of fetus occurred in 74% of the cases with PIH, while no any patients with IUGR fetus among the control group. 92% patients among uterine notches showed abnormal fetal outcome in the form of low birth weight, preterm delivery, LSCS for fetal distress, birth asphyxia or NICU admission of the neonate. Out of total 37 (74%) IUGR cases, 24 (65%) cases had fetoplacental Doppler abnormality. Out of total 6 cases with absent end-diastolic flow (AEDF) 4 cases had abnormal fetal outcome and 2 cases had delivered still-born babies. 20 out of 30 cases had abnormal fetal middle cerebral arterial Doppler (MCA) PI, out of which 19 patients had abnormal fetal outcome. 23 cases had abnormal CPR, out of them 20 (87%) cases had abnormal outcome and only 3 cases had normal fetal outcome. The parameters at the time of delivery are number of cases with delivery before 37 weeks of GA (63.3%), SGA babies (70%), LSCS for fetal distress (43.3%), and NICU admission (43.3%).Conclusions: Examining the maternal vessels using Doppler ultrasound, it is possible to determine the risk of complication developing in the course of pregnancy long before clinical signs of preeclampsia appear, so that therapeutic measures may be undertaken early

Complications of gynaecologic laparoscopy: an audit

Background: Minimal access surgery as a modality of treatment for various gynecologic conditions is rapidly gaining grounds in the recent years1. Approximately 30 years after its introduction; the use of laparoscopy in gynecology has evolved from diagnostic purposes into a more coordinated system for the repair or removal of diseased abdominal and pelvic organs. The rapid increase in the number of procedures being performed, the introduction of new equipment, and variability in the training of surgeons all contribute to the complication rate. The objective is to review complications associated with laparoscopic gynecological surgeries and identify associated risk factors.Methods: Hospital based descriptive observational study performed between January 2013 to December 2017 which included all gynecologic laparoscopies performed in present institute. Variables were recorded for patient characteristics, indication for surgery, length of hospital stay (in days), major and minor complications, conversions to laparotomy and postoperative complications. The laparoscopic procedures were divided into three subgroups: Diagnostic cases, tubal sterilization and Advanced operative laparoscopy.Results: Of all 3724 laparoscopies included, overall frequency of major was 1.96 %, and that of minor complications was 3.51%. Of 3724 laparoscopic procedures, 214 complications occurred (5.8% of all procedures) and one death occurred. The level of technical difficulty and existence of prior abdominal surgery were associated with a higher risk of major complications and conversions to laparotomy.Conclusions: Laparoscopic surgery has many advantages, but it is not without complications. Despite rapidly improving technical equipment’s and surgical skill; complication rates and preventable injuries demonstrate continuous pattern. Delayed recognition and intervention add to morbidity and mortality. Each laparoscopic surgeon should be aware of the potential complications, how they can be prevented and managed efficiently

Time dependence of Bragg forward scattering and self-seeding of hard x-ray free-electron lasers

Free-electron lasers (FELs) can now generate temporally short, high power x-ray pulses of unprecedented brightness, even though their longitudinal coherence is relatively poor. The longitudinal coherence can be potentially improved by employing narrow bandwidth x-ray crystal optics, in which case one must also understand how the crystal affects the field profile in time and space. We frame the dynamical theory of x-ray diffraction as a set of coupled waves in order to derive analytic expressions for the spatiotemporal response of Bragg scattering from temporally short incident pulses. We compute the profiles of both the reflected and forward scattered x-ray pulses, showing that the time delay of the wave $\tau$ is linked to its transverse spatial shift $\Delta x$ through the simple relationship $\Delta x = c\tau \cot\theta$, where $\theta$ is the grazing angle of incidence to the diffracting planes. Finally, we apply our findings to obtain an analytic description of Bragg forward scattering relevant to monochromatically seed hard x-ray FELs.Comment: 11 pages, 6 figure

A High Energy X-Ray and Neutron Scattering Study of Iron Phosphate Glasses Containing Uranium

The atomic structure of iron phosphate glasses containing uranium has been studied by complementary neutron and x-ray scattering techniques. by combining x-ray and neutron structure factors, detailed information about different pair interactions has been obtained. Most of the basic structural features such as coordination numbers and O-O and P-O distances in uranium containing glasses are the same as those in the base glass of batch composition 40Fe2O3-60P2O5 (mol %). However, the Fe-O distances change slightly with the addition of uranium. The observed structural parameters support a structural model in which the waste elements occupy voids in the Fe-O-P network, hence, not altering the basic structure of the parent iron phosphate glass

Fast by Nature - How Stress Patterns Define Human Experience and Performance in Dexterous Tasks

In the present study we quantify stress by measuring transient perspiratory responses on the perinasal area through thermal imaging. These responses prove to be sympathetically driven and hence, a likely indicator of stress processes in the brain. Armed with the unobtrusive measurement methodology we developed, we were able to monitor stress responses in the context of surgical training, the quintessence of human dexterity. We show that in dexterous tasking under critical conditions, novices attempt to perform a task's step equally fast with experienced individuals. We further show that while fast behavior in experienced individuals is afforded by skill, fast behavior in novices is likely instigated by high stress levels, at the expense of accuracy. Humans avoid adjusting speed to skill and rather grow their skill to a predetermined speed level, likely defined by neurophysiological latency

Polyhedral units and network connectivity in calcium aluminosilicate glasses from high-energy x-ray diffraction

Structure factors for Cax/2AlxSi1-xO2 glasses (x=0,0.25,0.5,0.67) extended to a wave vector of magnitude Q= 40 1/A have been obtained by high-energy x-ray diffraction. For the first time, it is possible to resolve the contributions of Si-O, Al-O and Ca-O coordination polyhedra to the experimental atomic pair distribution functions (PDF). It has been found that both Si and Al are four-fold coordinated and so participate in a continuous tetrahedral network at low values of x. The number of network breaking defects in the form of non-bridging oxygens (NBO's) increases slowly with x until x=0.5 (NBO's ~ 10% at x=0.5). By x=0.67 the network breaking defects become significant as evidenced by the significant drop in the average coordination number of Si. By contrast, Al-O tetrahedra remain free of NBO's and fully integrated in the Al/Si-O network for all values of x. Calcium maintains a rather uniform coordination sphere of approximately 5 oxygen atoms for all values of x. The results suggest that not only Si/Al-O tetrahedra but Ca-O polyhedra, too, play a role in determining the glassy structure