Spin-valley locking and bulk quantum Hall effect in a noncentrosymmetric Dirac semimetal BaMnSb2.

Spin-valley locking in monolayer transition metal dichalcogenides has attracted enormous interest, since it offers potential for valleytronic and optoelectronic applications. Such an exotic electronic state has sparsely been seen in bulk materials. Here, we report spin-valley locking in a Dirac semimetal BaMnSb2. This is revealed by comprehensive studies using first principles calculations, tight-binding and effective model analyses, angle-resolved photoemission spectroscopy measurements. Moreover, this material also exhibits a stacked quantum Hall effect (QHE). The spin-valley degeneracy extracted from the QHE is close to 2. This result, together with the Landau level spin splitting, further confirms the spin-valley locking picture. In the extreme quantum limit, we also observed a plateau in the z-axis resistance, suggestive of a two-dimensional chiral surface state present in the quantum Hall state. These findings establish BaMnSb2 as a rare platform for exploring coupled spin and valley physics in bulk single crystals and accessing 3D interacting topological states.

Acridine orange adsorption by zinc oxide/almond shell activated carbon composite: Operational factors, mechanism and performance optimization using central composite design and surface modeling.

Zinc Oxide/Activated Carbon Powder was used for the adsorptive removal of Acridine Orange dye (AO) from aqueous solution. The prepared composite material was characterized using XRD, XPS, SEM, EDS, FTIR, XRF, Raman, BET surface area and TGA/DTA. The adsorption isotherms, kinetics and thermodynamic studies of AO onto the ZnO-AC were thoroughly analyzed. The kinetic modeling data revealed that the adsorption of AO has a good adjustment to the pseudo-second-order model. Langmuir isotherm model is better fitted for adsorption data and the maximum adsorption capacity was found to be 909.1 mg/g at 313 K. The negative values of ΔG showed the spontaneous nature of the AO adsorption onto ZnO-AC. The results indicated the adsorption was pH dependent which is mainly governed by electrostatic attraction, hydrogen bonding and π-π interaction. Reusability test showed a low decrease in the removal performance of ZnO-AC due to the mesopore filling mechanism confirmed by BET analysis after adsorption. Also, thermal regeneration could deposit AO dye on the surface of the composite leading to the efficiency decrease. Finally, the effect of various parameters such as pH, temperature, contact time and initial dye concentration was studied using response surface methodology (RSM). The model predicted a maximum AO removal (99.42 ± 0.57%) under the optimum conditions, which was very close to the experimental value (99.32 ± 0.18%).

In Vitro Activities of Ertapenem and Imipenem against Clinical Extended Spectrum Beta-Lactamase-Producing Enterobacteriaceae Collected in Military Teaching Hospital Mohammed V of Rabat.

Objective. To study the sensitivity level of extended spectrum beta-lactamase-producing Enterobacteriaceae to Carbapenems (Imipenem, Ertapenem) marketed in Morocco and discusses the place of Ertapenem in the treatment of extended spectrum-beta-lactamase-producing. Materials and Methods. A retrospective study of 110 extended spectrum beta-lactamase-producing Enterobacteriaceae. Isolates obtained from blood cultures, superficial and deep pus, and catheters were conducted. The minimum inhibitory concentrations of Imipenem and Ertapenem were done by the E-test. The modified Hodge test was conducted for resistant or intermediate strains. Results. 99.1% of isolates were susceptible to Imipenem. For Ertapenem, 4 were resistant and 4 intermediate. The modified Hodge test was positive for all 08 isolates. A minimum inhibitory concentration comparison of K. pneumoniae, E. cloacae, and E. coli for Imipenem has noted a significant difference between E. cloacae on one hand and E. coli, K. pneumoniae on the other hand (P < 0.01). No significant difference was noted for minimum inhibitory concentration of Ertapenem. Conclusion. Our results confirm in vitro effectiveness of Ertapenem against extended spectrum beta-lactamase-producing Enterobacteriaceae as reported elsewhere. However, the emergence of resistance to Carbapenems revealed by production of carbapenemases in this study confirmed a necessary bacteriological documented infection before using Ertapenem.

Long-term follow-up of patients with mild to moderate drug-induced liver injury.

AIM: To evaluate the long-term prognosis of patients diagnosed with drug-induced liver injury, and the nature of the liver injury. METHODS: Patients with a diagnosis of drug-induced liver injury between 1994 and 2005 were identified in a university hospital clinic. Patients surviving drug-induced liver injury-associated liver failure were excluded. RESULTS: Seventy-seven cases were identified and those who were alive (69) were invited to attend follow-up. Of those patients who had died, none had died of liver disease. Of those patients who had survived, 59 were reviewed in the clinic. Patients had a median follow-up of 48 months. Before the diagnosis of drug-induced liver injury, nine had a chronic liver disease, four with autoimmune hepatitis, two with non-alcoholic liver disease, one each with non-alcoholic fatty liver disease, primary biliary cirrhosis and primary sclerosing cholangitis. There was no evidence of progression of their liver disease during follow-up. Among 50 patients without a known liver disease prior to the drug-induced liver injury, 10 had abnormal liver tests. Diagnostic work-up revealed alternative cause of liver disease in all except three patients (6%), who had asymptomatic abnormal liver tests (but normal bilirubin in all). CONCLUSIONS: Chronic abnormalities in liver tests, not explained by an identified liver disease, are very rare in patients previously diagnosed with drug-induced liver injury. This group of patients did not seem to have a clinically significant liver injury at long-term follow-up.

Drug-induced liver injury in a Swedish University hospital out-patient hepatology clinic.

BACKGROUND: Limited data exist on the proportion of drug-induced liver injury among out-patients seen in a hepatology clinic. AIM: To determine the proportion of drug-induced liver injury cases, and identify the most important agents and the nature of the liver injury. METHODS: A computerized diagnoses database in an out-patient hepatology clinic in a Swedish University hospital was analysed during the period 1995-2005. All suspected drug-induced liver injury cases were causality assessed with the International Consensus Criteria. RESULTS: A total of 1164 cases were seen for the first time during this period. Drug-induced liver injury with at least a possible causal relationship was found in 77 cases (6.6%), 38 (3.3%) of whom were referred for evaluation to the out-patient clinic whereas 3% had a follow-up after hospitalization of drug-induced liver injury. The median age was 58 years, 43 (56%) were females, a hepatocellular pattern was observed in 37 cases (48%), cholestatic in 31 (40%) and mixed in 12%. Antibiotics were the most common agents causing drug-induced liver injury followed by non-steroidal anti-inflammatory drugs, with diclofenac most often responsible for the drug-induced liver injury. CONCLUSIONS: Drug-induced liver injury cases constituted 6% of all out-patients and 3% of referrals and occurred more often in women. Antibiotics and diclofenac were the most common causes of drug-induced liver injury among out-patients.

A new quantitative in vitro for the detection of latex-specific IgE antibodies.

Immediate-type hypersensitivity to latex allergens has resulted in anaphylactic shock and death in numerous reported cases. The allergenic proteins of latex are contained within the natural rubber extract of Hevea brasiliensis and are eluted into the final product during the manufacturing process. The quantity and types of latex allergens found in different latex products depends on the manufacturing process. Not all of these allergens are available for use in the latex prick skin test, and as a result, such tests may not be conclusive. Furthermore, application of such allergens to the skin of undiagnosed hypersensitive individuals may have harmful effects on their health. Therefore, it is important to be able to utilize in vitro methods, which reliably identify latex allergy without placing hypersensitive individuals at risk. We have developed a relatively simple and new enzyme immuno-assay (EIA) method for the detection of latex allergy. This in vitro method is quantitative and allows for the classification of allergy to latex in a short time. In comparative studies, ninety-nine serum specimens with documented clinical history of latex allergy were tested by this method, and the results paralleled those of the skin prick test performed by an independent group. The data showed that the specificity and sensitivity of our assay approaches 97.5% and 100%, respectively. We conclude that, by using a simple assay, the detection of specific IgE to latex proteins may be valuable for screening individuals and for the diagnosis of allergy to latex.

Effects of weight and center of gravity location of head-supported devices on neck loading.

A comprehensive study of the effect of Head-Supported Devices (HSDs) on neck loading during helicopter accidents is presented. The new Articulated Total Body (ATB) model which treats the neck as a deformable segment was used for crash simulation. Different categories of human and manikin subjects were considered under several crash scenarios. Simulations were theoretically designed to include a wide range of HSDs by changing their weights and center of gravity (CG) locations relative to the head, and studying the effects of these changes. Since HSDs were only theoretically included in the model, detachment of specific detachable devices used in most military applications was not modeled in the study. Hence, two typical detachable devices were modeled and selected simulations were repeated and compared not only to provide a measure of accuracy for the original results but also to see the effect of separation of these devices from the helmet.

Injury risk for research subjects with spina bifida occulta in a repeated impact study: a case review.

Spina bifida occulta (SBO) occurs in 18-34% of the normal U.S. population. Recently, 16.5% of normal, asymptomatic male soldier volunteer candidates in a U.S. Army Aeromedical Research Laboratory ride motion study were excluded from the study because they had SBO at one vertebral level. Disqualifying this percentage of screened research subject candidates threatened the timely completion of the schedule-intense protocol. Although one study suggests that SBO at spinal level S1 has a higher incidence of posterior disc herniation, the preponderance of clinical literature reports that spina bifida occulta is not a medical problem. The impact literature indicates that lumbosacral vertebral bodies fracture at 7.14 kN in static compression and 20+ G during dynamic vertical impacts. In this paper, we examined the human data observed in ejection seat incidents, the rationale for excluding volunteers with single level SBO and the path of axial load transmission through the lumboscral spine. Based on the findings, we concluded that research volunteers with single level SBO are not at increased risk for injury and recommended inclusion of these volunteers in future studies involving repeated axial impacts due to ride motion.

A correlative investigation of simulated occupant motion and accident report in a helicopter crash.

BACKGROUND: In the late 1980's, an Army Apache helicopter crashed during a training mission, resulting in fatal injuries to the rear seat pilot and survivable injuries to the front seat copilot. U.S. Army investigators assessed the aircraft damage and aircrew injuries, and examined the helmets, restraint systems, and crashworthy seats. HYPOTHESIS: Computer simulations that approximate an actual crash event can provide insightful output (human body motions and forces on the human body) that illuminates our understanding of the injury dynamics and the effect of safety systems designed to minimize injury. METHODS: Crash kinematics and vehicle accelerations were derived from the investigation and inferred from the aircraft damage, and input to a computer-based analytical simulation that calculated the dynamics and forces to which the crew were exposed. RESULTS: We treat the simulation like a looking glass into the event, revealing how and when safety devices could have responded during the crash, and the nature of injury-producing forces experienced by the occupants. Computer simulated whole-body and head-neck motion are graphically displayed, along with plots of joint forces, seat stroke, harness belt acceleration, and occupant accelerations. CONCLUSIONS: The calculated motions and forces indicated that injuries found in the accident were likely, hence the simulation may indeed be representative of the actual event.

Mycologic study of tinea capitis in Qatar.

The causative dermatophytic species of tinea capitis were identified in 91 patients in Qatar. Microsporum canis was the most common isolated organism (86.81%) followed by Microsporum ferrugineum and Trichophyton violaceum. A gray patch type of tinea capitis was the predominant presentation (87.91%), and the disease was more prevalent among Qatari boys.