Lu3+ doping induced photoluminescence enhancement in novel high-efficiency Ba3Eu(BO3)3 red phosphors for near-UV-excited warm-white LEDs

Ba₃Eu(BO₃)₃ (BEB) and Lu³⁺ doped BEB red phosphors were successfully synthesized by a high-temperature solid-state reaction method. X-ray diffraction (XRD) patterns, excitation and emission spectra, decay lifetimes, CIE coordinates, internal quantum efficiency, and thermal stability of these phosphors were systematically studied. Under 395 nm excitation, these phosphors exhibited high-brightness red emissions centred at 611 nm. In addition, it was found that doping appropriate amounts of Lu³⁺ ions into BEB phosphors can improve their photoluminescence intensity and internal quantum efficiency. The integrated emission intensity of BEB:0.3Lu³⁺ phosphor was about 1.34 times that of BEB phosphor. Compared with commercial red phosphor Y₂O₂S:Eu³⁺, BEB:0.3Lu³⁺ phosphor showed better color purity (91.4%) and higher emission intensity (about 3.25 times). Surprisingly, the BEB:0.3Lu³⁺ phosphor had a high internal quantum efficiency of almost 87%, which was higher than that of 83% for BEB phosphors. Meanwhile, the BEB:0.3Lu³⁺ phosphors also exhibited good thermal stability with activation energy around 0.14 eV, and the integrated emission intensity at 423 K remained about 52% of that at 303 K. Finally, by using commercial BaMgAl₁₀O₁₇:Eu²⁺ blue phosphors, commercial (Ba,Sr)₂SiO₄:Eu²⁺ green phosphors, as-prepared BEB:0.3Lu³⁺ red phosphors and a 395 nm near-ultraviolet-emitting light-emitting diode (LED) chip, a prototype warm white LED device was fabricated, which showed good color rendering index (CRI = 84.7) and low correlated color temperature (CCT = 3377 K).

Novel high-efficiency Ba₃Eu(BO₃)₃:Lu³⁺ red phosphors with internal quantum efficiency as great as 87% were developed for near-UV-excited warm-white LEDs.     

Differential larvicidal efficacy of four species of <Emphasis Type="Italic">Vitex</Emphasis> against <Emphasis Type="Italic">Culex quinquefasciatus</Emphasis> larvae

The early fourth instar larvae of Culex quinquefasciatus, reared in the laboratory were used for larvicidal assay with leaf extracts of Vitex negundo, Vitex trifolia, Vitex peduncularis and Vitex altissima. The methanol extracts of the four species possessed varying levels of larvicidal nature. The highest larvicidal activity was found with the extract of V. trifolia (LC₅₀ = 41.41 ppm) followed by V. peduncularis (LC₅₀ = 76.28 ppm), V. altissima (LC₅₀ = 128.04 ppm) and V. negundo (LC₅₀ = 212.57 ppm).     

Prevalence of acquired MDR-TB and HIV co-infection

BACKGROUND: Mounting prevalence of primary and acquired multidrug-resistant tuberculosis in India is a sorry reminder of all round failure in our fight against tuberculosis and also of the necessity for new effective strategies. OBJECTIVES: (1) To assess the prevalence and pattern of drug resistant pulmonary tuberculosis among treated patients or on those on treatment without adequate response and (2) to evaluate HIV seropositivity among MDR-TB patients. METHODS: Pulmonary TB patients, who had at least six months of unsuccessful anti-tuberculous treatment were selected for the study. Their sputum specimens were examined for M. tuberculosis culture and drug sensitivity pattern and serological examinations for HIV infection were carried out. RESULTS: Sputum specimens of 618 patients' (61.8%) of a total of 1000 examined had shown culturable M. tuberculosis. Four hundred ninty-five patients (49.5%) were found to expectorate tubercle bacilli resistant to one or more anti TB drugs. MDR-TB was detected in 339 patients (33.9%). HIV seropositivity among MDR-TB was 4.42%. Significantly, 245 patients (24.5%) had tubercle bacilli resistant to one or more reserve drugs too (ethionamide, kanamycin and/or ofloxacin). CONCLUSIONS: Prevalence of MDR-TB was high in the study population. It is essentially an acquired condition. Its association with HIV disease was at present on the lower side, an observation contrary to published western literature. Higher rates of resistance for reserve drugs (ethionamide, kanamycin and/or ofloxacin) in patients who never had these drugs in their earlier treatment schedules suggest the possibility of emerging spontaneous drug resistant mutants.     

Chemical constituents and larvicidal property of the essential oil of <Emphasis Type="Italic">Blumea mollis</Emphasis> (D. Don) Merr. against <Emphasis Type="Italic">Culex quinquefasciatus</Emphasis>

The essential oil from the leaves of Blumea mollis was extracted and the chemical constituents and the larvicidal against Culex quinquefasciatus effects studied. The analyses of gas chromatography (GC) and GC-mass spectroscopy (GC-MS) revealed that the leaf essential oil of B. mollis contained 39 compounds, and the major chemical compounds identified were linalool (19.43%), gamma-elemene (12.19%), copaene (10.93%), estragole (10.81%), Allo-ocimene (10.03%), gamma-terpinene (8.28%) and Allo-aromadendrene (7.44%). The essential oil had significant toxic effect against early fourth-instar larvae of C. quinquefasciatus with LC50=71.71 and LC90=143.41 ppm. The results could be useful in search of newer, safer and more effective natural larvicidal agent against C. quinquefasciatus.     

Air Permeability of Maraging Steel Cellular Parts Made by Selective Laser Melting

Additive manufacturing, such as selective laser melting (SLM), can be used to manufacture cellular parts. In this study, cellular coupons of maraging steels are prepared through SLM by varying hatch distance. Air flow and permeability of porous maraging steel blocks are obtained for samples of different thickness based on the Darcy equation. By reducing hatch distance from 0.75 to 0.4 mm, the permeability decreases from 1.664 × 10⁻⁶ mm² to 0.991 × 10⁻⁶ mm² for 4 mm thick coupons. In addition, by increasing the thickness from 2 to 8 mm, the permeability increases from 0.741 × 10⁻⁶ mm² to 1.345 × 10⁻⁶ mm² at 16.2 J/mm³ energy density and 0.14 MPa inlet pressure. Simulation using ANSYS-Fluent is conducted to observe the pressure difference across the porous coupons and is compared with the experimental results. Surface artifacts and the actual morphology of scan lines can cause the simulated permeability to deviate from the experimental values. The measured permeability of maraging steel coupons is regression fit with both energy density and size of samples which provide a design guideline of porous mold inserts for industry applications such as injection molding.     

Opioid-Mediated HIV-1 Immunopathogenesis

Despite the ability of combination antiretroviral therapy to dramatically suppress viremia, the brain continues to be a reservoir of HIV-1 low-level replication. Adding further complexity to this is the comorbidity of drug abuse with HIV-1 associated neurocognitive disorders and neuroHIV. Among several abused drugs, the use of opiates is highly prevalent in HIV-1 infected individuals, both as an abused drug as well as for pain management. Opioids and their receptors have attained notable attention owing to their ability to modulate immune functions, in turn, impacting disease progression. Various cell culture, animal and human studies have implicated the role of opioids and their receptors in modulating viral replication and virus-mediated pathology both positively and negatively. Further, the combinatorial effects of HIV-1/HIV-1 proteins and morphine have demonstrated activation of inflammatory signaling in the host system. Herein, we summarized the current knowledge on the role of opioids on peripheral immunopathogenesis, viral immunopathogenesis, epigenetic profiles of the host and viral genome, neuropathogenesis of SIV/SHIV-infected non-human primates, blood-brain-barrier, HIV-1 viral latency, and viral rebound. Overall, this review provides recent insights into the role of opioids in HIV-1 immunopathogenesis.

Graphical abstract

     

Antioxidant gene therapy against neuronal cell death

Oxidative stress is a common hallmark of neuronal cell death associated with neurodegenerative disorders such as Alzheimer's disease, Parkinson's disease, as well as brain stroke/ischemia and traumatic brain injury. Increased accumulation of reactive species of both oxygen (ROS) and nitrogen (RNS) has been implicated in mitochondrial dysfunction, energy impairment, alterations in metal homeostasis and accumulation of aggregated proteins observed in neurodegenerative disorders, which lead to the activation/modulation of cell death mechanisms that include apoptotic, necrotic and autophagic pathways. Thus, the design of novel antioxidant strategies to selectively target oxidative stress and redox imbalance might represent important therapeutic approaches against neurological disorders. This work reviews the evidence demonstrating the ability of genetically encoded antioxidant systems to selectively counteract neuronal cell loss in neurodegenerative diseases and ischemic brain damage. Because gene therapy approaches to treat inherited and acquired disorders offer many unique advantages over conventional therapeutic approaches, we discussed basic research/clinical evidence and the potential of virus-mediated gene delivery techniques for antioxidant gene therapy.     

Estudo prospectivo randômico,duplo‐cego e controlado comparando tramadol,clonidina e dexmedetomidina para tremores pós‐raquianestesia

Introduction

Shivering, a common intraoperative problem under spinal anesthesia increases the oxygen consumption considerably and is uncomfortable and distressing to the patient, anesthesiologist as well as surgeon. The present study was designed to explore the effectiveness of tramadol, clonidine and dexmedetomidine in the treatment of post spinal anesthesia shivering and to look for their adverse effects.