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2D materials for sensing applications offer several advantages—high absorption in thin layers, the lack of surface dangling bonds or major defects, ease of materials synthesis and device fabrication, and relaxed substrate lattice-matching requirements. We theoretically explore two 2D materials, hexagonal boron phosphide and hexagonal boron arsenide, for possible infrared sensing and hyperspectral applications. Using first principles, we calculate the total energy of formation, band structures, and absorption coefficient of monolayer and bilayer materials. We evaluate the bandgap and absorption coefficient of bilayers as a function of layer stacking, number of layers, and applied field across the layers. We find that with a choice of stacking order, number of layers, and applied field, the material can be chosen appropriately for sensing of short-, mid-, or long-wavelength infrared radiation. Furthermore, the absorption is increased in these materials with applied electric fields. With the ability to dynamically change the bandgap with an external electric field, this class of materials is ideally suited for continuous hyperspectral sensing in the infrared. [ABSTRACT FROM AUTHOR]

In the search for materials alternate to bulk HgCdTe for high performance infrared imaging applications, colloidal quantum dots (CQDs), particularly HgTe CQDs, have gained traction owing to acceptable detector performance with easy preparation and low cost. In this article, we evaluate α -Sn CQDs, an environmentally less reactive and less toxic alternative to HgTe, for infrared sensing applications. Ab initio density functional theory calculations are used to study the shape-dependent stability, electronic bandgap, and absorption coefficient of α -Sn CQD nanoparticles (NPs). We consider three possible CQD shape constructions—Wulff, shell-by-shell, and spherical. The CQD of Wulff construction is predicted to be the most stable. However, we find that the size, not the shape, of the NP has a strong effect on the bandgap and absorption coefficient. Consequently, a sharp absorption edge is expected even in an ensemble of CQDs with different shapes. Importantly, the shape determines the position of the band edges with respect to vacuum, and thus offers a possibility of choosing the shape to improve alignment with the energy levels of ligands to enable efficient drift transport, instead of a slower and less efficient hopping transport. [ABSTRACT FROM AUTHOR]

Leishmaniasis is one of the neglected tropical diseases. Studies show that the poor knowledge about epidemiological aspects of leishmaniasis within communities causes the collapse of existing disease control programs. Therefore, the present study focuses on a detailed survey of the existing awareness among the threatened population in the Medawachchiya Public Health Inspector’s (PHI) Area in the Anuradhapura District, Sri Lanka, aiming to assist the health staff to organize community-based vector control programs effectively in the future. Assessment of the awareness of residents of two hundred and seventy households (n = 270) from 10 Grama Niladhari Divisions (GNDs) was carried out by using a structured questionnaire. Among 143 females and 134 males, only 75.1% had knowledge about the disease, 5.8% (n = 16) of the participants knew only about the vector, and 28.9% (n = 80) knew about control methods. The study showed a considerable lack of awareness about the disease among the studied population. The study found that age and education levels had significant impacts on knowledge, attitudes, and practices. However, factors like gender, marital status, occupation, income, and expenses did not show significant correlations. The present study suggests huge scope for greater achievements in community-related vector control methods by implementing a continuous educational program.

Adolescence is a crucial phase of growth and development in the life course, and healthy nutrition is essential during this period. The objective of this study was to explore the perceptions regarding the implementation of relevant nutrition policies for adolescents in Sri Lanka. The study is qualitative, employing a "phenomenology" approach. The study was conducted in the central province of Sri Lanka, with participants including adolescents (n = 18), public health inspectors (n = 3), parents (n = 12), canteen owners (n = 3), schoolteachers (n = 3), and principals (n = 3). Data were collected through interviews and analyzed using the framework analysis method. Results indicated that adolescents' awareness of relevant policy statements is poor. Implementing nutrition policies related to adolescents in school settings and at the community level remains insufficient. In conclusion, future research should further evaluate the overall implementation of nutrition policies directed at adolescents. This will help policymakers to enhance and improve relevant policy guidelines. [ABSTRACT FROM AUTHOR]

The prevalence and severity of many chronic pain syndromes differ across sex, and recent studies have identified differences in immune signalling within spinal nociceptive circuits as a potential mediator. Although it has been proposed that sex-specific pain mechanisms converge once they reach neurons within the superficial dorsal horn, direct investigations using rodent and human preclinical pain models have been lacking. Here, we discovered that in the Freund's adjuvant in vivo model of inflammatory pain, where both male and female rats display tactile allodynia, a pathological coupling between KCC2-dependent disinhibition and N-methyl-D-aspartate receptor (NMDAR) potentiation within superficial dorsal horn neurons was observed in male but not female rats. Unlike males, the neuroimmune mediator brain-derived neurotrophic factor (BDNF) failed to downregulate inhibitory signalling elements (KCC2 and STEP61) and upregulate excitatory elements (pFyn, GluN2B and pGluN2B) in female rats, resulting in no effect of ex vivo brain-derived neurotrophic factor on synaptic NMDAR responses in female lamina I neurons. Importantly, this sex difference in spinal pain processing was conserved from rodents to humans. As in rodents, ex vivo spinal treatment with BDNF downregulated markers of disinhibition and upregulated markers of facilitated excitation in superficial dorsal horn neurons from male but not female human organ donors. Ovariectomy in female rats recapitulated the male pathological pain neuronal phenotype, with BDNF driving a coupling between disinhibition and NMDAR potentiation in adult lamina I neurons following the prepubescent elimination of sex hormones in females. This discovery of sexual dimorphism in a central neuronal mechanism of chronic pain across species provides a foundational step towards a better understanding and treatment for pain in both sexes. [ABSTRACT FROM AUTHOR]

Dysregulated excitability within the spinal dorsal horn is a critical mediator of chronic pain. In the rodent nerve injury model of neuropathic pain, BDNF-mediated loss of inhibition (disinhibition) gates the potentiation of excitatory GluN2B N-methyl-d-aspartate receptor (NMDAR) responses at lamina I dorsal horn synapses. However, the centrality of this mechanism across pain states and species, as well as the molecular linker involved, remain unknown. Here, we show that KCC2-dependent disinhibition is coupled to increased GluN2B-mediated synaptic NMDAR responses in a rodent model of inflammatory pain, with an associated downregulation of the tyrosine phosphatase STEP61. The decreased activity of STEP61 is both necessary and sufficient to prime subsequent phosphorylation and potentiation of GluN2B NMDAR by BDNF at lamina I synapses. Blocking disinhibition reversed the downregulation of STEP61 as well as inflammation-mediated behavioural hypersensitivity. For the first time, we characterize GluN2B-mediated NMDAR responses at human lamina I synapses and show that a human ex vivo BDNF model of pathological pain processing downregulates KCC2 and STEP61 and upregulates phosphorylated GluN2B at dorsal horn synapses. Our results demonstrate that STEP61 is the molecular brake that is lost following KCC2-dependent disinhibition and that the decrease in STEP61 activity drives the potentiation of excitatory GluN2B NMDAR responses in rodent and human models of pathological pain. The ex vivo human BDNF model may thus form a translational bridge between rodents and humans for identification and validation of novel molecular pain targets. [ABSTRACT FROM AUTHOR]

Background: Assessment of the availability of essential medicines, in rural areas of countries with free state health care system, is scarce. Dependence on essential medicines among the population in rural sector is considered to be high. Assessing the availability of essential medicines in selected state owned primary and secondary health care institutions of a rural district will help to identify areas where improvement is needed.Methods: A descriptive cross sectional study, covering selected five primary and one secondary care institutions of a rural Sri Lankan district, was conducted. The national list of essential medicines, Sri Lanka was used as the check list and the guidelines of the WHO-Health Action International were adapted.Results: The secondary care institution recorded an overall availability of 71%, whereas the average overall availability of the primary care institutions was 56%. Central dispensaries recorded the lowest availability. Lack of availability of medicines needed for the management of chronic kidney disease, snake bite and poisoning was noted.Conclusions: Availability of essential medicines in most of the primary and the secondary care institutions were fairly high. Deficiency in medicines needed for the management of emergencies was noted. A need based annual estimate of medicines based on an essential medicine list is suggested. [ABSTRACT FROM AUTHOR]

Information is lacking on the effects toxic environmental metals may have on the 26S proteasome. The proteasome is a primary vehicle for selective degradation of damaged proteins in a cell and due to its role in cell proliferation, inhibition of the proteasome has become a target for cancer therapy. Metals are essential to the proteasome's normal function and have been used within proteasome-inhibiting complexes for cancer therapy. This study evaluated the association of erythrocyte metal levels and proteasome chymotrypsin-like (CT-like) activity in age- and race-matched prostate cancer cases ( n = 61) and controls ( n = 61). Erythrocyte metals were measured by inductively coupled plasma mass spectrometry (ICP-MS). CT-like activity was measured by proteasome activity assay using a fluorogenic peptide substrate. Among cases, significant correlations between individual toxic metals were observed ( r(arsenic-cadmium) = 0.49, p < 0.001; r(arsenic-lead) = 0.26, p = 0.04, r(cadmium-lead) 0.53, p < 0.001), but there were no significant associations between metals and CT-like activity. In contrast, within controls there were no significant associations between metals, however, copper and lead levels were significantly associated with CT-like activity. The associations between copper and lead and proteasome activity (r(copper-CT-like) = −0.28, p = 0.002 ; r(lead-CT-like) = 0.23, p = 0.011) remained significant in multivariable models that included all of the metals. These findings suggest that biologically essential metals and toxic metals may affect proteasome activity in healthy controls and, further, show that prostate cancer cases and controls differ in associations between metals and proteasome activity in erythrocytes. More research on toxic metals and the proteasome in prostate cancer is warranted. [ABSTRACT FROM AUTHOR]

The activation of tris(dimethylamino)borane towards reaction with a chiral methimazole by N-methylimidazole has been used to prepare the first example of a chiral tris(methimazolyl)borate ligand. Coordination of this neutral ligand to Ru(ii) has been achieved by reaction with [(p-cymene)RuCl2]2 to provide a single diastereomer complex in which the chirality of the methimazolyl substituents dictate the chirality of the bicyclo[3.3.3]cage formed by the ligand on coordination to the metal. The alternative approach to chiral tris(methimazolyl)borate ligands involving the introduction of a chiral group onto the boron atom has been explored by replacing N-methylimidazole in the above reaction by chiral oxazolines as activating bases in reaction with simple methimazole. However, although the B(NMe2)3 is activated to reaction with methimazole by these oxazolines, an intramolecular oxazoline ring-opening by a coordinated methimazolyl sulfur occurs and prevents the successful synthesis of these ligands. [ABSTRACT FROM AUTHOR]

Describes the development of a series of noncomplexing buffers which rely on the use of sterically hindered tertiary alkylamines. Presence of two protonable sites in the compounds studied; Determination of the acid dissociation constants for the constant in aqueous solution; Calculation of apparent enthalpy and entropy values.

Using high-precision Penning trap mass spectrometry at the Low Energy Beam and Ion Trap facility at the National Superconducting Cyclotron Laboratory we have measured the Q values of the fourth-order forbidden β decay and electron capture of 50V and the double electron capture Q value of 50Cr with the results Qβ(50V)=1038.1(1) keV, QEC(50V)=2208.7(1) keV, and Q2EC(50Cr)=1170.5(1) keV. In addition, we have measured the atomic masses of 46,47,49,50Ti,50,51V, and 50,52-54Cr, reducing uncertainties by factors of up to three compared with the most recent atomic mass evaluation (Ame2016) [Chin. Phys. C 41, 030003 (2017)]. Our results are in good agreement with Ame2016 for 46,47,49,50Ti and 50,54Cr and show deviations of up to ∼1keV(2.5σ) for 50,51V and 50,54Cr. [ABSTRACT FROM AUTHOR]

Using Penning trap mass spectrometry, we have performed a precise determination of the Q value for the highly forbidden β decay of 113Cd. An independent measurement of the Q value fixes the end-point energy in a fit to the 113Cd β-decay spectrum. This provides a strong test of systematics for detectors that have observed this decay, such as those developed for ββ-decay searches in cadmium and other isotopes. It will also aid in the theoretical description of the β-decay spectrum. The result, Qβ=323.89(27)keV, agrees at the 1.3σ level with the value obtained from the 2012 Atomic Mass Evaluation [Chin. Phys. C 36, 1603 (2012)], but is a factor of almost four more precise. We also report improved values for the atomic masses of 113Cd, 113In, and 112Cd. [ABSTRACT FROM AUTHOR]