Gate Controlled Excitonic Emission in Quantum Dot Thin Films.

Formation of charged trions is detrimental to the luminescence quantum efficiency of colloidal quantum dot (QD) thin films as they predominantly undergo nonradiative recombination. In this regard, control of charged trion formation is of interest for both fundamental characterization of the quasi-particles and performance optimization. Using CdSe/CdS QDs as a prototypical material system, here we demonstrate a metal-oxide-semiconductor capacitor based on QD thin films for studying the background charge effect on the luminescence efficiency and lifetime. The concentration ratio of the charged and neutral quasiparticles in the QDs is reversibly controlled by applying a gate voltage, while simultaneous steady-state and time-resolved photoluminescence measurements are performed. Notably, the photoluminescence intensity is modulated by up to 2 orders of magnitude with a corresponding change in the effective lifetime. In addition, chip-scale modulation of brightness is demonstrated, where the photoluminescence is effectively turned on and off by the gate, highlighting potential applications in voltage-controlled electrochromics.

Efficiency Roll-Off Free Electroluminescence from Monolayer WSe2.

Exciton-exciton annihilation (EEA) is a nonradiative process commonly observed in excitonic materials at high exciton densities. Like Auger recombination, EEA degrades luminescence efficiency at high exciton densities and causes efficiency roll-off in light-emitting devices. Near-unity photoluminescence quantum yield has been demonstrated in transition metal dichalcogenides (TMDCs) at all exciton densities with optimal band structure modification mediated by strain. Although the recombination pathways in TMDCs are well understood, the practical application of light-emitting devices has been challenging. Here, we demonstrate a roll-off free electroluminescence (EL) device composed of TMDC monolayers tunable by strain. We show a 2 orders of magnitude EL enhancement from the WSe2 monolayer by applying a small strain of 0.5%. We attain an internal quantum efficiency of 8% at all injection rates. Finally, we demonstrate transient EL turn-on voltages as small as the band gap. Our approach will contribute to practical applications of roll-off free optoelectronic devices based on excitonic materials.

The influence of eroding Djallonke genotype on the incidence of diseases and mortalities in Sahelian x Djallonke cross-bred sheep.

Despite cross-breeding of Djallonke and Sahelian sheep due to the higher growth rate and final body weight of the Sahelian breeds over time, little scientific evidence exists on the ability of the crosses to withstand diseases compared to their Djallonke parents. A study involving 700 Djallonke and two crosses of the Djallonke and Sahelian breeds (50% Sahel × 50% Djallonke, 75% Sahel × 25% Djallonke) was conducted, and documented incidence of diseases, parasites and mortalities in these animals. Enteritis, Ehrlichia ruminantium and orf were more prevalent in 25% Djallonke than both 100% and 50% Djallonkes. Similarly, pneumonia was more prevalent in 50% Djallonkes, individuals of all age groups and females than all other genotypes, adults and males, respectively. Enteritis prevalence was also higher in lambs and males than animals of all age groups and females, respectively. Coccidiosis was more prevalent in individuals of all age groups and males, than lambs and females, respectively. More abscess and trauma cases were found in males than females. Higher levels of tapeworm and flea infestations were seen in lambs than weaners and adults. Conversely, more mange mite and tick infestations were seen in adults than weaners and lambs. Higher mortality rates were recorded in all other genotypes, lambs and females than in 100% Djallonke, all other age groups and males, respectively. Higher case fatality rate was recorded in haemoncosis than taeniasis cases. The Sahel x Djalloke crosses are more susceptible to infectious diseases and record higher mortality rates than the pure Djallonke genotypes.

An Audit on Overnight Transfusion Practice in A Teaching Hospital in Malaysia.

INTRODUCTION: Overnight transfusion (OT) is the blood transfusion taking place from 9pm to 8am. During this period, patients are exposed to increased risk of errors. This cross-sectional study aims to determine the incidence and practice of OT in Universiti Kebangsaan Malaysia Medical Centre. MATERIALS & METHODS: Data from all OT in June and mid-July 2017 were collected from recipients' cards, transfusion request forms and patient's case files, regarding discipline involved, indications, time intervals from request of blood transfusion to the completion of OT on patients, monitoring of patients and adverse reactions. RESULTS: A total of 1285 transfusion cases were identified during the study period. 216 (16.8%) cases were OT while the 1069 (83.2%) cases were non-OT. Surgery discipline has the highest (30.1%) OT. The indications of OT were acute clinical need: 82.9%, less acute clinical need: 13.9% and no clinical need: 3.2%. A huge delay (average: 5 hours 40 minutes) in starting transfusion after grouping and crossmatching (GXM) completion was noted. Besides, 25.9% cases took <4 hours to complete OT; 83.4% cases did not have proper transfusion monitoring and three transfusion reactions were reported. DISCUSSION: Although most of the OT cases had appropriate clinical indications, the transfusion can be commenced earlier at day time rather than overnight. Cases without absolute indication should avoid OT. The poor monitoring of patient during OT had posed risks to patients' life if an adverse transfusion reaction happened. The major reason for OTs was a huge delay in starting transfusion after the GXM completion. The contravention of 4-hour infusion rule increased the patients' risk of developing bacterial sepsis. The practice of OT should be discouraged wherever possible except for clinically indicated cases.

Exploring the potential of neutron imaging for life sciences on IMAT.

Neutron imaging has been employed in life sciences in recent years and has proven to be a viable technique for studying internal features without compromising integrity and internal structure of samples in addition to being complementary to other methods such as X-ray or magnetic resonance imaging. Within the last decade, a neutron imaging beamline, IMAT, was designed and built at the ISIS Neutron and Muon Source, UK, to meet the increasing demand for neutron imaging applications in various fields spanning from materials engineering to biology. In this paper, we present the first neutron imaging experiments on different biological samples during the scientific commissioning of the IMAT beamline mainly intended to explore the beamline's capabilities and its potential as a noninvasive investigation tool in fields such as agriculture (soil-plants systems), palaeontology and dentistry. LAY DESCRIPTION: Neutrons form a highly penetrating radiation passing through matter without damaging or structurally modifying it, a property that makes them the ideal tool for many kinds of complementary material investigations. Moreover, the strong interaction of neutrons with hydrogen and their ability to distinguish between hydrogen and deuterium with no radiation damage make neutrons a good probe for imaging biological specimens. The recent technological developments of sources and detectors improved the capabilities of neutron imaging instruments and also have facilitated the use of neutron imaging on a much wider scale than before. Neutron imaging is proving its advantages as being complementary to other known methods of investigation such as X-ray imaging or magnetic resonance imaging and it is no surprise that it is not only employed in engineering or archaeology, but also in life sciences. This definitely opens new perspectives for a more interdisciplinary approach in contemporary science. Within the last decade a neutron imaging beamline, IMAT, was designed and built at the ISIS Neutron and Muon Source, UK, to meet the increasing demands of researchers from different fields, spanning from materials engineering to biology. The results presented here, acquired from first measurements on different biological samples during the scientific commissioning of IMAT beamline show the instrument capability and its suitability to palaeontology, agriculture (soil-plants systems) or dentistry applications.

Recent updates on electronic cigarette aerosol and inhaled nicotine effects on periodontal and pulmonary tissues.

E-cigarette-derived inhaled nicotine may contribute to the pathogenesis of periodontal and pulmonary diseases in particular via lung inflammation, injurious, and dysregulated repair responses. Nicotine is shown to have antiproliferative properties and affects fibroblasts in vitro, which may interfere in tissue myofibroblast differentiation in e-cig users. This will affect the ability to heal wounds by decreasing wound contraction. In periodontics, direct exposure to e-vapor has been shown to produce harmful effects in periodontal ligament and gingival fibroblasts in culture. This is due to the generation of reactive oxygen species/aldehydes/carbonyls from e-cig aerosol, leading to protein carbonylation of extracellular matrix and DNA adducts/damage. A limited number of studies regarding the effects of e-cig in oral and lung health are available. However, no reports are available to directly link the deleterious effects on e-cigs, inhaled nicotine, and flavorings aerosol on periodontal and pulmonary health in particular to identify the risk of oral diseases by e-cigarettes and nicotine aerosols. This mini-review summarizes the recent perspectives on e-cigarettes including inhaled nicotine effects on several pathophysiological events, such as oxidative stress, DNA damage, innate host response, inflammation, cellular senescence, profibrogenic and dysregulated repair, leading to lung remodeling, oral submucous fibrosis, and periodontal diseases.

Vigour in West African Dwarf kids within the first 24 h post-partum.

One hundred and fifty West African Dwarf (WAD) kids were tested at the National Goats Breeding Station to determine the effects of some neonatal factors on their vigour levels within the first 24 h post-partum. The kids were also tested to establish the relationship between maternal weight, rectal temperature, times of first standing and sucking, sucking period and vigour. The distance covered (in meters) by a kid towards its mother during a 5-min test period was considered as vigour trait. Vigour levels increased significantly (p < 0.05) with increasing age within the first 24 h post-partum. Kids born to second parity mothers had higher (p < 0.05) vigour than those born to first parity mothers. Similarly, high birth weight kids had higher (p < 0.05) vigour levels than low birth weight kids. Weak positive and negative correlations (p < 0.05), respectively, were found between vigour and rectal temperature, and vigour and the time of first successfully standing. However, there was moderate positive correlation (p < 0.01) between vigour and sucking period. The time it took for the newborn kid to stand up for the first time also correlated weakly and negatively (p < 0.01) with the duration of sucking by the newborn within the first 5 min of accessing the teat. Vigour within the first 24 h post-partum in WAD kids increased with increasing age, parity and birth weight and might be responsible for the earlier and longer sucking time and periods, respectively, in high birth weight kids and those dropped by multiparous does.

Assessment of Natural Radioactivity Levels and Radiation Hazards in Agricultural and Virgin Soil in the State of Kedah, North of Malaysia.

The activity concentrations of naturally occurring radionuclides 226Ra, 232Th, and 40K were determined in 30 agricultural and virgin soil samples randomly collected from Kedah, north of Malaysia, at a fertile soil depth of 0-30 cm. Gamma-ray spectrometry was applied using high-purity germanium (HPGe) gamma-ray detector and a PC-based MCA. The mean radioactivity concentrations of 226Ra, 232Th, and 40K were found to be 102.08 ± 3.96, 133.96 ± 2.92, and 325.87 ± 9.83 Bq kg-1, respectively, in agricultural soils and 65.24 ± 2.00, 83.39 ± 2.27, and 136.98 ± 9.76 Bq kg-1, respectively, in virgin soils. The radioactivity concentrations in agricultural soils are higher than those in virgin soils and compared with those reported in other countries. The mean values of radium equivalent activity (Raeq), absorbed dose rates D (nGy h-1), annual effective dose equivalent, and external hazard index (Hex) are 458.785 Bq kg-1, 141.62 nGy h-1, and 0.169 mSv y-1, respectively, in agricultural soils and 214.293 Bq kg-1, 87.47 nGy h-1, and 0.106 mSv y-1, respectively, in virgin soils, with average Hex of 0.525. Results were discussed and compared with those reported in similar studies and with internationally recommended values.

Effects of season on the reproductive organ and plasma testosterone concentrations in guinea cocks (Numida meleagris).

The physiological basis of seasonal breeding in the guinea fowl (Numida meleagris) still remains unknown, despite the socioeconomic importance of these birds, particularly in Ghana. A study involving a total of 50 local guinea cocks was conducted, and documented gross anatomical and histological differences in the reproductive organs of breeding and non-breeding male guinea fowls. The study also compared peripheral testosterone concentrations in breeding and non-breeding cocks. Seasonal differences in variables measured were determined using two-tailed t-test/Mann-Whitney U-test. All comparisons were made at 5% level of significance. Breeding males had significantly (P = 0.000) higher anatomical biometric parameters than their non-breeding counterparts. Also, breeding birds had thicker (P = 0.000) phalli than their non-breeding counterparts. Histologically, regressing testis was characterized by the presence of sloughed off cells and increased debris in the tubular lumen and within the excurrent duct system, collapsed tubules and reduction in tubular lumen. Germ and Sertoli cell populations and nuclear diameters and actual seminiferous tubular diameter and length in regressing testes were significantly (P = 0.000) lower than in active testes. Leydig cell nuclear diameters and populations were also significantly (P = 0.000) reduced. Relative volume of seminiferous tubules in the testis, testicular sperm production/mg testis and per testis and peripheral testosterone concentrations were all higher (P < 0.05) in breeding than non-breeding testis. The ducts in the epididymal region also saw significant (P < 0.05) reductions in luminal diameters in non-breeding birds. Significant regression in anatomical and histological structures of the guinea cock reproductive tract occurred during the non-breeding season, and lower peripheral testosterone concentrations may be responsible for this phenomenon.

Effects of season on the reproductive organs and steroid hormone profiles in guinea hens (Numida meleagris).

The study documented gross anatomical and histological differences in the reproductive organs of 28 breeding and non-breeding female guinea fowls. Peripheral progesterone and 17ß-oestradiol concentrations were also compared in breeding and non-breeding hens. In non-breeding females, all ovarian and oviducal gross anatomical features had significantly regressed. Histologically, some of the changes in a regressing oviduct include systematic changes in height and size of all epithelial cells in all regions of the duct, absence/sparse ciliation of portions of surface epithelium in the magnum, isthmian and uterine regions, general loss of cytoplasmic mass, reduction in size and degeneration of tubular glands. Mucosal folds in all regions of the oviduct except the infundibular lip were higher in breeding females. No difference was found between the two groups in plasma progesterone concentrations. Breeding females, however, had higher peripheral oestradiol concentrations than non-breeding females. About 2 h prior to oviposition, plasma oestradiol concentrations peaked at 2.4-fold (230 pg/ml) compared with baseline concentration and plasma progesterone concentrations by nearly 9-fold (5.29 ng/ml) of baseline. Significant regression and changes in the histological structure of the ovary and oviduct had occurred in non-breeding females, and lower peripheral oestrogen concentrations may be responsible for this phenomenon.

Mycotic bronchial artery aneurysmal rupture in the early stage of lung abscess: A case report.

Symptomatic bronchial artery aneurysm warrants urgent intervention. It has a known association with pulmonary infection caused by Staphylococcus aureus. We hereby report an elderly lady with a ruptured left superior bronchial artery mycotic aneurysm. She was in the early stages of treatment for a left lung abscess. She had multiple episodes of haemoptysis following which she underwent a left lower lobectomy. Presentation of lung abscess with a concurrent ruptured mycotic aneurysm warrants early surgical intervention and can be curative as seen in this case.

Barlow's Repair: Light in the Dark Tunnel: A Case Report Could Omit 'Light in A Dark Tunnel'.

Barlow's disease has a complex pathology requiring reconstructive surgery. Despite the complicated surgery it holds a positive outcome. We report a successful case of Barlow's disease who underwent mitral valve reconstructive surgery at our centre. Post-operative echocardiography shows a well-functioning repaired mitral valve without significant mitral regurgitation.

Raman Spectroscopy Investigation of Phonon Behavior in ZnO-Buffered MgB2 Tapes: Exploring Lattice Dynamics and Anharmonicity.

We investigated the phonon behavior of ZnO-buffered MgB2 tapes with varying ZnO buffer layer thicknesses using polarized Raman spectroscopy at room and cryogenic temperatures. Polar plots from integrated angle-resolved polarized Raman spectroscopy (ARPRS) at room temperature revealed substantial distortion in the boron plane geometry due to lattice mismatch among the MgB2 film, ZnO buffer layer, and Hastelloy substrate. This distortion significantly affects the electron-phonon coupling (EPC) constant, λ, which we calculated using the modified McMillan equation by Allen-Dynes in relation to the superconducting transition temperature (Tc) of the sample. At cryogenic temperatures, our investigation of the E2g mode exhibited a notable phonon hardening effect of up to ∼4.1%, correlated with the ZnO buffer layer thickness. Furthermore, analysis of the anharmonic E2g phonon mechanism through line width (full width at half maximum) revealed damping behavior, indicating an additional coupling mechanism within the sample that varies with the temperature. This unique Raman scattering behavior potentially elucidates the high Tc mechanism of MgB2, which is underestimated by traditional EPC calculations. Additionally, increasing the thickness of the ZnO layer is predicted to alleviate the distortion in the boron plane geometry, thereby promoting MgB2 toward its inherent electron-phonon superconducting nature by mitigating the additional coupling mechanisms. Understanding how the ZnO buffer layer influences the phonon dynamics and EPC in MgB2 will provide critical insights into optimizing its superconducting properties and advancing its practical applications in high-performance superconducting devices.

An Albumin, Neutrophil, and Lymphocyte-Related Risk Estimation Tool in Hospitalised Patients.

AIM: The neutrophil-to-lymphocyte ratio (NLR) is commonly used as a prognostic indicator for microbiological and inflammatory conditions in clinical settings. However, the quotient to albumin levels, which is another nutritional and clinical predictor, may also have an interesting diagnostic and prognostic value. This study aimed to primarily investigate the predictive performances of the neutrophils to albumin and lymphocytes ratio (NALR) compared to the NLR in predicting poor outcomes during hospital admission, particularly the decomposition of respiratory, renal, liver, and circulatory systems, resulting in longer hospital stays or mortality. METHODS: An observational study was performed on a cohort of 270 hospitalised patients admitted to Rashid bin Al-Hussein Military Hospital during the period from October 2023 to early November 2023. The study specifically targeted adult patients (age >17 years) who had a minimum of 80% availability of their initial and follow-up data during admission. We dichotomised all eligible test patients into two groups: Group I, which represented better outcomes of interest, and Group II, which represented poorer outcomes of interest. Statistically, we conducted binary logistic, receiver operating, and sensitivity analyses to explore the predictive performances and indices for NALR and NLR. We also conducted chi-square and independent T analyses to uncover the distribution rates of the independent variables across Groups I and II. We considered a p-value of less than 0.05 as the level of significance. RESULTS: Out of a total sample size of 270, 82 patients (30.37%) were allocated to Group I, and 188 patients (69.63%) were allocated to Group II. Males outnumbered females in this study by 184 (68.1%) to 86 (31.9%). Patients in the study had an average age of 58.08±10.02 years. The average hospitalisation took 13.71±6.38 days, significantly longer in Group II compared to Group I (15.43±6.76 days vs. 9.77±2.69 days, p-value<0.05). We found that the area under the receiver operating characteristic (ROC) curves was estimated at [0.808±0.031 (0.748-0.868), p-value=0.000] and [0.667±0.034 (0.601-0.733), p-value=0.000] for NALR and NLR, respectively. The optimal operating thresholds for NALR and NLR were 1.5 and 5.37, with sensitivities and specificities of 86.7% versus 73.4% and 70.73% versus 70.73%, respectively. CONCLUSION: The proposed NALR showed superior predictive performance, sensitivity, and correlation compared to the parent NLR. Both tools can be used in clinical practice to prioritise clinical and pharmacotherapeutics for hospitalised patients based on unfavourable outcomes.

Pericardial neo-aorta to bridge long segment defects after infected aortic reconstructions.

Aortic prosthetic graft infection is a rare, potentially fatal complication. Surgical explantation of the infected native and prosthetic material with sufficient debridement has sometimes been limited by the lack of a suitable conduit to bridge the residual long segment defect. We describe the implantation of a bovine pericardial fashioned neo-aorta to manage this problem.

Comparison of salbutamol and ipratropium bromide versus salbutamol alone in the treatment of acute severe asthma.

The use of nebulized Ipratropium bromide, quaternary anticholinergic bronchodilators in combination with beta-agonist for the treatment of acute asthma in adults is controversial. In a view of different recommendation the present study is undertaken in Bangladeshi patients. Combination of inhaled Ipratropium bromide and Salbutamol provides greater bronchodilatation than mono therapy with Salbutamol alone in acute severe asthma. Patients of severe asthma (PEFR <50% of predicted) were enrolled into control group (Salbutamol only) and case (Salbutamol + Ipratropium bromide) group. After measurement of peak expiratory flow, patient received 3 doses of 2.5 mg Salbutamol (n=40) only or 3 doses of both 2.5mg Salbutamol and 500mcg Ipratropium bromide at an interval of 20 minutes (n=40) through a jet nebulizer. Peak flow was reassessed 30 & 60 minutes after treatment. Peak flow at baseline was similar in two groups. Then at 30 minutes after nebulization, the mean±SD percentage increase in peak flow was greater in combination group (60.01±35.01%) than Salbutamol group (44.47±25.03%) with difference of 16% (p=0.025). At 60 minutes the percentage increase in peak flow was about 32% greater in combination group than Salbutamol group (94.44±33.70% vs. 62.57±29.26%, p=0.000) and combination group reached percentage predicted peak flow more than 60% while Sabutamol group did not. Ipratropium Bromide and Salbutamol nebulized combinedly have better bronchodilating effect than Salbultamol alone in acute severe asthma.

Prevalence and determinants of condom utilization among people living with HIV/AIDS in Egypt.

Condoms are an integral part of HIV/AIDS prevention, yet their use is affected by several factors. The purpose of this study was to determine the prevalence of condom use and the psychological and behavioural determinants among people living with HIV/AIDS in Egypt. Focus group discussions were used to develop the study tool (questionnaire interview) geared towards eliciting knowledge, attitudes and beliefs about condoms among 338 confirmed HIV-positive persons attending fixed voluntary counselling and testing centres in 8 governorates in Egypt. The prevalence of condom use was 45.0% in regular sexual relations and only 18.1% in casual relations. The determinants of condom use were: type of partner, serostatus of partner, antiretroviral intake, beliefs and attitudes towards condom use and to HIV infection. The study shows that special efforts need to be made to change the attitudes of people living with HIV/AIDS towards condom use.

Looking beyond legality: understanding the context of female sex workers in greater Cairo, Egypt.

Data on demographic, social and behavioural characteristics of female sex workers in greater Cairo are very scarce. A cross-sectional study was conducted with 431 randomly selected sex workers after mapping of sites where they gather. Data collection was performed by direct interviewing using a questionnaire sheet covering sociodemographic data and sexual history with paying and non-paying partners. More than one half of participants (52.7%) were aged < 30 years. Only 39.3% were exclusively working as sex workers while the rest had other jobs beside sex work. Almost 70% were responsible for deperidants. The age of first selling sex was < 15 years for 4.7% of the women and 15-25 years for 58.7%. Unwanted pregnancies were experienced by 36.2% and 34.8% had had an abortion. Many participants had ever been arrested by the police (71.2%). The study has provided some useful background data for further studies in this very sensitive area of research.

Awake Craniotomy: A Case Series of Anaesthetic Management using a Combination of Scalp Block, Dexmedetomidine and Remifentanil in Hospital Universiti Sains Malaysia.

Awake craniotomy is a brain surgery in patients who are kept awake when it is indicated for certain intracranial pathologies. The anaesthetic management strategy is very important to achieve the goals of the surgery. We describe a series of our first four cases performed under a combination of scalp block and conscious sedation. Scalp block was performed using a mixture of ropivacaine 0.7% and adrenaline 5 5µg/ ml administered to the nerves that innervate the scalp. Conscious sedation was achieved with a combination of two recently available drugs in our country, dexmedetomidine (selective α 2-agonist) and remifentanil (ultra-short acting opioid). Remifentanil was delivered in a target controlled infusion (TCI) mode.

Anomalous thickness dependence of photoluminescence quantum yield in black phosphorous.

Black phosphorus has emerged as a unique optoelectronic material, exhibiting tunable and high device performance from mid-infrared to visible wavelengths. Understanding the photophysics of this system is of interest to further advance device technologies based on it. Here we report the thickness dependence of the photoluminescence quantum yield at room temperature in black phosphorus while measuring the various radiative and non-radiative recombination rates. As the thickness decreases from bulk to ~4 nm, a drop in the photoluminescence quantum yield is initially observed due to enhanced surface carrier recombination, followed by an unexpectedly sharp increase in photoluminescence quantum yield with further thickness scaling, with an average value of ~30% for monolayers. This trend arises from the free-carrier to excitonic transition in black phosphorus thin films, and differs from the behaviour of conventional semiconductors, where photoluminescence quantum yield monotonically deteriorates with decreasing thickness. Furthermore, we find that the surface carrier recombination velocity of black phosphorus is two orders of magnitude lower than the lowest value reported in the literature for any semiconductor with or without passivation; this is due to the presence of self-terminated surface bonds in black phosphorus.