Holographic imaging of antiferromagnetic domains with in-situ magnetic field.

Lensless coherent x-ray imaging techniques have great potential for high-resolution imaging of magnetic systems with a variety of in-situ perturbations. Despite many investigations of ferromagnets, extending these techniques to the study of other magnetic materials, primarily antiferromagnets, is lacking. Here, we demonstrate the first (to our knowledge) study of an antiferromagnet using holographic imaging through the 'holography with extended reference by autocorrelation linear differential operation' technique. Energy-dependent contrast with both linearly and circularly polarized x-rays are demonstrated. Antiferromagnetic domains and topological textures are studied in the presence of applied magnetic fields, demonstrating quasi-cyclic domain reconfiguration up to 500 mT.

Identifying Luminescent Boron Vacancies in h-BN Generated Using Controlled He+ Ion Irradiation.

The defect emission from h-BN at 1.55 eV is interesting as it enables optical readout of spins. It is necessary to identify the nature of the relevant point defects for its controlled introduction. However, it is challenging to engineer point defects in h-BN without changing the local atomic structure. Here, we controllably introduce boron vacancies in h-BN using an ultrahigh spatial resolution and low-energy He+ ion beam. By optimizing the He+ ion irradiation conditions, we control the quantity and location of defects spatially and along the depth of h-BN to achieve a robust photoluminescence emission at 1.55 eV from 10 K to room temperature. We show that as-generated defects activate an additional Raman mode at 1295 cm-1. Electron energy loss spectroscopy confirms introduction of boron vacancies without modification of the local h-BN crystal structure. Our results provide a deterministic strategy to create scalable boron vacancy emitters in h-BN for quantum photonics.

Experience of "One Stop TB Diagnostic Solution" Model in Engaging a Private Laboratory for End-to-End Diagnostic Services in the National TB Elimination Program in Hisar, India.

The complete diagnostic evaluation of tuberculosis based on its drug-resistance profile is critical for appropriate treatment decisions. The TB diagnostic landscape in India has been transformed with the scaling-up of WHO-recommended diagnostics, but challenges remain with specimen transportation, completing diagnostic assessment, turnaround time (TAT), and maintaining laboratories. Private laboratories have demonstrated efficiencies for specimen collection, transportation, and the timely testing and issue of results. A one-stop TB diagnostic model was designed to assess the feasibility of providing end-to-end diagnostic services in the Hisar district of Haryana state, India. A NTEP-certified private laboratory was engaged to provide the services, complementing the existing public sector diagnostic services. A total of 10,164 specimens were collected between May 2022 and January 2023 and these were followed for the complete diagnostic assessment of Drug-Susceptible TB (DS-TB) and Drug-Resistant TB (DR-TB) and the time taken for issuing results. A total of 2152 (21%) patients were detected with TB, 1996 (93%) Rifampicin-Sensitive and 134 (6%) with Rifampicin-Resistant TB. Nearly 99% of the patients completed the evaluation of DS-TB and DR-TB within the recommended TAT. The One-Stop TB/DR-TB Diagnostic Solution model has demonstrated that diagnostic efficiencies could be enhanced through the strategic purchase of private laboratory services.

Isolation and characterization of bioactive lactoferrin from camel milk by novel pH-dependent method for large scale production.

The present article exemplifies a novel method to isolate highly purified bioactive lactoferrin from camel milk. Cytotoxicity of lactoferrin against the Hela cells was used to evaluate its bioactivity. SDS-PAGE and LC-MS analysis was done for its identification and characterization. The purified camel milk lactoferrin was found to be 708 amino acids in length with a molecular weight of 77.3 kDa and a pI value of 8.24. This pH-dependent isolation procedure ensures the retention of bioactive lactoferrin from camel milk. The importance of the present work lies in its simplicity and scalability for manufacturing bioactive lactoferrin at an industrial level.

Predictors of knowledge and use of long-lasting insecticidal nets for the prevention of malaria among the pregnant women in Pakistan.

BACKGROUND: Malaria is endemic to Pakistan with high prevalence among pregnant women and linked with maternal anaemia, intrauterine growth retardation, preterm birth, and low birth weight. The use of long-lasting insecticidal nets (LLINs) is a proven and cost-effective intervention preventing malaria among pregnant women. The present study aimed to explore predictors of knowledge and use of LLINs among pregnant women in Pakistan. METHODS: This was part of a quasi-experimental study of 200 pregnant women conducted in a rural district of Sindh province in Pakistan. Data were collected using Malaria Indicator Survey questionnaires developed by Roll Back Malaria Partnership to end Malaria Monitoring and Evaluation Reference Group. Pregnant women and mothers with newborns of six months of age were interviewed in their homes. RESULTS: The age of the women was from 18 to 45, two thirds of the respondents (72.5%) were uneducated and married (77%). Majority (92%) of the women had received antenatal care during pregnancy, and 29.5% women had received counseling on malaria during their antenatal care visits. Multiple linear regression showed that the type of latrine was the most significant (ß = 0.285, p < 0.001) determinant of knowledge about malaria among pregnant women followed by the death of a newborn (ß = 0.271, p < 0.001). The use of mobile phone was the most significant (ß = 0.247, p < 0.001) predictor of usage of LLINs among pregnant women followed by the death of a newborn (ß = 0.232, p < 0.05). CONCLUSIONS: Maternal education, type of latrine, use of mobile phone, malaria during previous pregnancy and newborn death were strong predictors of knowledge and use of LLINs in pregnant women in Pakistan. There is a need to scale-up programmes that aim to create awareness regarding malaria among pregnant women. Mobile phone technology can be used to implement awareness programmes focusing on malaria prevention among women.

A Barium Titanate-on-Oxide Insulator Optoelectronics Platform.

Electro-optic modulators are among the most important building blocks in optical communication networks. Lithium niobate, for example, has traditionally been widely used to fabricate high-speed optical modulators due to its large Pockels effect. Another material, barium titanate, nominally has a 50 times stronger r-parameter and would ordinarily be a more attractive material choice for such modulators or other applications. In practice, barium titanate thin films for optical waveguide devices are usually grown on magnesium oxide due to its low refractive index, allowing vertical mode confinement. However, the crystal quality is normally degraded. Here, a group of scandate-based substrates with small lattice mismatch and low refractive index compared to that of barium titanate is identified, thus concurrently satisfying high crystal quality and vertical optical mode confinement. This work provides a platform for nonlinear on-chip optoelectronics and can be promising for waveguide-based optical devices such as Mach-Zehnder modulators, wavelength division multiplexing, and quantum optics-on-chip.

Modification of thermal transport in few-layer MoS2 by atomic-level defect engineering.

Molybdenum disulfide (MoS2) has attracted significant attention due to its good charge carrier mobility, high on/off ratio in field-effect transistors and novel layer-dependent band structure, with potential applications in modern electronic, photovoltaic and valleytronic devices. Despite these advantages, its thermal transport property has often been neglected until recently. In this work, we probe phonon transport in few-layer MoS2 flakes with various point defect concentrations enabled by helium ion (He+) irradiation. For the first time, we experimentally show that Mo-vacancies greatly impede phonon transport compared to S-vacancies, resulting in a larger reduction of thermal conductivity. Furthermore, Raman characterization shows that the in-plane Raman-sensitive peak E2g1 was red-shifted with increasing defect concentration, corresponding to the gradual damage of the in-plane crystalline networks and the gradual reduction in the measured thermal conductivity. Our work provides a practical approach for atomic-level engineering of phonon transport in two-dimensional (2D) layered materials by selectively removing elements, thus holding potential applications in designing thermal devices based on various emerging 2D materials.

Nanometer-Scale Uniform Conductance Switching in Molecular Memristors.

One common challenge highlighted in almost every review article on organic resistive memory is the lack of areal switching uniformity. This, in fact, is a puzzle because a molecular switching mechanism should ideally be isotropic and produce homogeneous current switching free from electroforming. Such a demonstration, however, remains elusive to date. The reports attempting to characterize a nanoscopic picture of switching in molecular films show random current spikes, just opposite to the expectation. Here, this longstanding conundrum is resolved by demonstrating 100% spatially homogeneous current switching (driven by molecular redox) in memristors based on Ru-complexes of azo-aromatic ligands. Through a concurrent nanoscopic spatial mapping using conductive atomic force microscopy and in operando tip-enhanced Raman spectroscopy (both with resolution <7 nm), it is shown that molecular switching in the films is uniform from hundreds of micrometers down to the nanoscale and that conductance value exactly correlates with spectroscopically determined molecular redox states. This provides a deterministic molecular route to obtain spatially homogeneous, forming-free switching that can conceivably overcome the chronic problems of robustness, consistency, reproducibility, and scalability in organic memristors.

Effectiveness of a health education intervention on the use of long-lasting insecticidal nets for the prevention of malaria in pregnant women of Pakistan: a quasi-experimental study.

BACKGROUND: About one quarter of pregnant women in the population of Pakistan are using long-lasting insecticide-treated bed nets (LLINs) for prevention of malaria. Past research reported that adequate information and education would act as mediator to change behaviour among patients for prevention of malaria infection. The effective use of LLINs would contribute to reduction of disease burden caused by malaria. The aim of this study was to determine the effectiveness of health education on the adoption of LLINs among pregnant women living in Tharparkar, a remote district in Sindh Province, Pakistan. METHODS: A quasi-experimental study design with control and intervention groups was conducted with 200 pregnant women (100 in each group). Women in the intervention group were provided with health education sessions on malaria for 12 weeks, while those in the control group obtained routine information from lady health workers (LHWs). Pre- and post-intervention assessment was done of knowledge about malaria and use of LLIN, which was statistically analysed using descriptive statistics and difference in difference (DID) multivariable regression analysis to test effectiveness of the intervention. RESULTS: Baseline was conducted with 200 pregnant women. Demographic characteristics were similar in both groups with slight differences in age, education, income, type of latrine, and source of drinking water. There were no significant differences between mean knowledge and use of LLINs scores between groups at baseline. However, the estimated DID value after the intervention was 4.170 (p < 0.01) and represents an increase in scores of knowledge in the intervention group compared to control. Similarly DID value of 3.360 (p < 0.05) showed an increase in use of LLINs score after the intervention which was significant, showing that the intervention had a positive effect. CONCLUSIONS: Results proved that health education could be an effective intervention for improving knowledge and usage of LLINs among pregnant women for the prevention of malaria. Such educational interventions have a positive potential to be implemented at larger scale by incorporating them into routine health sessions provided by health workers.

Analytical and semi-preparative enantioresolution of (RS)-ketorolac from pharmaceutical formulation and in human plasma by HPLC.

An efficient, simple, validated, analytical and semi-preparative HPLC method has been developed for direct enantioresolution of (RS)-Ketorolac (Ket) using monochloro-methylated derivatives of cellulose and amylose, i.e. cellulose (tris-3-chloro-4-methylphenylcarbamate) and amylose (tris-5-chloro-2-methylphenylcarbamate) as chiral stationary phases (CSPs) with photo diode array detection at 320 nm. Enantioresolution was carried out in samples of human plasma spiked with (RS)-Ket under normal and reversed-phase elution modes with suitable mobile phase compositions. The effect of nature of alcohols (MeOH, EtOH, PrOH and n-BuOH) and other solvents (MeCN and MeOH) as organic modifiers in the mobile phase was investigated on the separation performance of two CSPs in terms of retention and separation of enantiomers. The best resolution was observed on cellulose-based CSP using EtOH, while using 2-PrOH (15%) and amylose-based CSP obtained the highest retention. Under reversed-phase elution mode the best enantioseparation was observed using 30% MeCN with ammonium formate buffer. The elution order of enantiomers was ascertained by determining specific rotations. The limit of detection and quantitation values were 5 and 15.5 ng/mL for each enantiomer of (RS)-Ket, respectively. Copyright © 2016 John Wiley & Sons, Ltd.

Application of optically pure amines as chiral auxiliaries to develop trichloro-s-triazine-based new chiral derivatizing reagents for reversed-phase high-performance liquid chromatographic enantioseparation of DL-selenomethionine.

(R)-(+)-naphthylethyl amine and (S)-(+)-1-benzyl-3-aminopyrrolidine were incorporated as chiral auxiliaries, by nucleophilic substitution of chlorine atoms, in cyanuric chloride (CC) or its 6-butoxy derivative. There were obtained four new chiral derivatizing reagents (CDRs) as two dichloro and two monochloro triazine reagents. The CDRs so obtained were characterized and their optical purity was ascertained. Diastereomers of dl-selenomethionine were synthesized under microwave irradiation for 60 or 90 s (at 80% power of 800 W). Reversed-phase high-performance liquid chromatographic separation of diastereomers was carried out on a C18 column using mixtures of acetonitrile with aqueous trifluoroacetic acid as mobile phase. The detection was made at 230 nm using a photodiode array detector. The separation behaviors in terms of retention times and resolutions were compared. The separation method was validated for limit of detection, linearity, accuracy, precision, and recovery.

(S)-Naproxen as a platform to develop chiral derivatizing reagent for reversed-phase high-performance liquid chromatographic enantioseparation of analytes having a carbonyl functional group.

(S)-Naproxen was used to synthesize a chiral reagent, (S)-2-(6-methoxynaphthalen-2-yl)propanehydrazide, by itsreaction with hydrazine hydrate in the presence of dicyclohexylcarbodiimide as coupling agent. The reagent was characterized and its chiral purity was established. It was used as a chiral derivatizing reagent for the synthesis of hydrazone diastereomers, under microwave irradiation, of certain chiral aldehydes and ketones. The respective diastereomers were separated by reversed-phase high-performance liquid chromatography using a binary solvent combination containing trifluoroacetic acid. The diastereomers were detected at 231 nm. The method was validated for accuracy, precision, and limit of detection (LOD). For a series of hydrazones the LOD was found to be in the range 1.62-1.65 pmol/mL.

Acute renal failure associated with malaria.

BACKGROUND: Malaria has protean clinical manifestations and acute renal failure (ARF) is one of its serious complications and could be life threatening. This study was carried out to describe the clinical characteristics and factors associated with adverse out come in patients with malarial acute renal failure. METHODS: Data of 46 Patients with ARF and smear positive malaria was analyzed further among all cases of ARF presented to us at Nephrology department of Jinnah Postgraduate Medical Centre, Karachi from January 2003 to December 2004. Results were expressed as mean, standard deviation and range. RESULTS: Among 237 patients with ARF of diverse etiology, 46(19.4%) developed ARF due to falciparum malaria. The male to female ratio was 3.6:1. Oliguria was seen in 76.09% on admission, and 78.26% required dialysis. In addition to ARF, most of the patients had at least one other manifestation of severe malaria. 35(76.06%) patients recovered completely while 11(23.91%) died in early dialysis. Prolonged disease duration, severe ARF, cerebral malaria, hyperbilirubinaemia, and disseminated intravascular coagulopathy (DIC) were poor prognostic factors. CONCLUSION: Falciparum malaria associated with ARF is a life threatening condition, but early presentation and intervention with appropriate anti-malarial and dialysis therapy is associated with improved survival and recovery of renal function. Early dialysis treatment in patients with severe falcipaum malaria and signs of deteriorating renal function is recommended.

COMBINED SPINAL AND EPIDURAL ANAESTHESIA FOR ABDOMINAL SURGERY: A NEW TECHNIQUE.

Combined spinal and epidural anaesthesia was used in 50 patients undergoing abdominal surgery. A fixed dose of 1.0 mL of 5 per cent lignocaine was injected intrathecally in all cases followed by 10 mL of 0.5 per cent bupivacaine epidurally, using "needle through needle" technique in the same lumbar intervertebral space. Subsequently epidural catheter was passed for top-up doses and postoperative analgesia. The advantages of this technique observed were immediate onset of intense block of prolonged, controllable duration and no incidence of post-spinal headache. Five cases developed intraoperative hypotension which required correction. No patient developed any complications of spinal and epidural anaesthesia.