Oligourea helix bundle binds detergents with diverse polar head groups.

Here we report a series of crystal structures (and accompanying biophysical data) of an array of diverse detergent guests bound to an oligourea foldamer helix bundle. These results significantly increase our structural and chemical understanding of aqueous guest recognition by oligourea foldamers and will aid the design of further functionalised oligourea-based self-assemblies.

Distilling Nonlocality in Quantum Correlations.

Nonlocality, as established by the seminal Bell's theorem, is considered to be the most striking feature of correlations present in spacelike separated events. Its practical application in device independent protocols, such as secure key distribution, randomness certification, etc., demands identification and amplification of such correlations observed in the quantum world. In this Letter we study the prospect of nonlocality distillation, wherein, by applying a natural set of free operations (called wirings) on many copies of weakly nonlocal systems, one aims to generate correlations of higher nonlocal strength. In the simplest Bell scenario, we identify a protocol, namely, logical OR-AND wiring, that can distill nonlocality to a significantly high degree starting from arbitrarily weak quantum nonlocal correlations. As it turns out, our protocol has several interesting facets: (i) it demonstrates that a set of distillable quantum correlations has nonzero measure in the full eight-dimensional correlation space, (ii) it can distill quantum Hardy correlations by preserving its structure, (iii) it shows that (nonlocal) quantum correlations sufficiently close to the local deterministic points can be distilled by a significant amount. Finally, we also demonstrate efficacy of the considered distillation protocol in detecting postquantum correlations.

Adaptive Binding of Alkyl Glycosides by Nonpeptidic Helix Bundles in Water: Toward Artificial Glycolipid Binding Proteins.

Amphipathic water-soluble helices formed from synthetic peptides or foldamers are promising building blocks for the creation of self-assembled architectures with non-natural shapes and functions. While rationally designed artificial quaternary structures such as helix bundles have been shown to contain preformed cavities suitable for guest binding, there are no examples of adaptive binding of guest molecules by such assemblies in aqueous conditions. We have previously reported a foldamer 6-helix bundle that contains an internal nonpolar cavity able to bind primary alcohols as guest molecules. Here, we show that this 6-helix bundle can also interact with larger, more complex guests such as n-alkyl glycosides. X-ray diffraction analysis of co-crystals using a diverse set of guests together with solution and gas-phase studies reveals an adaptive binding mode whereby the apo form of the 6-helix bundle undergoes substantial conformational change to accommodate the hydrocarbon chain in a manner reminiscent of glycolipid transfer proteins in which the cavity forms upon lipid uptake. The dynamic nature of the self-assembling and molecular recognition processes reported here marks a step forward in the design of functional proteomimetic molecular assemblies.

Exfoliation of black phosphorus in ionic liquids.

We report the characterization and formation of sonication-assisted liquid phase exfoliation of bulk black phosphorus (BP) crystals with the incorporation of two representative ionic liquids (ILs) ([Emim][Tf2N] and [Bmim][Tf2N]) as green dispersing media was attempted, which resulted in stable dispersion of multi-layer BP flakes with unsuspected high oxidation resistance and chemical/structural integrity due to the presence of IL layer on top of BP flakes. There are two unveiled issues for the generation of BP dispersion in ILs. First, thin films of BP flakes can be simply prepared through our approach. Because self-oxidation of BP in ambient condition can be significantly minimized in ILs, vacuum filtration step can be adopted to produce BP thin films in ambient condition. Second, the binding of IL molecules on BP flakes has been firstly demonstrated by the time-of-flight secondary ion mass spectrometry characterization. In addition to the exploitation of ILs as the green solvents with less environmental harmfulness, IL-based exfoliation of BP might be easily scalable because harsh control of atmospheric oxygen and moisture is unnecessary in this approach.

Mussel-inspired synthesis of boron nitride nanosheet-supported gold nanoparticles and their application for catalytic reduction of 4-nitrophenol.

Gold nanoparticle (AuNP)-decorated boron nitride nanosheet (BNNS) was successfully prepared through the simultaneous reduction of Au(3+) ions and the growth of AuNPs on polydopamine (PDA)-grafted BNNS. Both BNNS-AuNP and PDA-BNNS are successfully synthesized in an aqueous buffer solution (pH 8.5) in the absence of any chemical reducing agent and organic reaction, which is therefore environmentally friendly and highly beneficial for the mass production of green catalysts from 2D nanomaterials. BNNS-AuNP showed remarkable dispersion stability in aqueous media and revealed high catalytic efficiency for the reduction of nitrophenol as (4-NP) into 4-aminophenol (4-AP) within 8 min in water. The 2D structural feature of BNNS-AuNP also enables isolation and recycling of catalyst from 4-AP through the ultracentrifugation, which shows the retention of more than 60% of catalytic activity of BNNS-AuNP after five repetitions of the of recycling steps.

Boron nitride nanosheets decorated with silver nanoparticles through mussel-inspired chemistry of dopamine.

Boron nitride nanosheet (BNNS) decorated with silver nanoparticles (AgNPs) was successfully synthesized via mussel-inspired chemistry of dopamine. Poly(dopamine)-functionalized BNNS (PDA-BNNS) was prepared by adding dopamine into the aqueous dispersion of hydroxylated BNNS (OH-BNNS) at alkaline condition. AgNPs were decorated on PDA-BNNS through spontaneous reduction of silver cations by catechol moieties of a PDA layer on BNNS, resulting in AgNP-BNNS with good dispersion stability. Incorporation of PDA on BNNS not only played a role as a surface functionalization method of BNNS, but also provided a molecular platform for creating very sophisticated two-dimensional (2D) BNNS-based hybrid nanomaterials such as metal nanoparticle-decorated BNNS.

Enablers and barriers to rotavirus vaccine coverage in Assam, India- A qualitative study.

Background: Estimates suggest that 78,000 children died due to rotavirus gastroenteritis annually between 2011 and 2013 in India. The north eastern state of Assam reported 38.4% pediatric diarrheal admissions testing positive for rotavirus. Rotavirus vaccine (RVV) was introduced in Assam in 2017 following which the National Family Health Survey-5 (NFHS-5) (2019) revealed low RVV coverage in Assam with wide variation between the districts. the current study was conceptualized and undertaken to capture the enablers and barriers to RVV coverage in Assam. Methods: Qualitative study conducted in 5 randomly selected districts in Assam. Participants (key informants) were recruited by purposive sampling at each level of the health system including healthcare officials, service providers and caregivers based on availability. Thirty-five in-depth interviews (IDIs) and five focus group discussions (FGDs) were conducted. Interviews were tape recorded and transcribed. Data was coded and analyzed using the thematic framework approach. Results: Findings from the qualitative data collection were collated and analyzed under 7 identified themes. Difficult terrain, limited service provider availability and no catch-up training for new recruits were some of the barriers to RVV coverage. In contrast, Information, Education & Communication (IEC) in vernacular language, RVV safety profile, development partner support and adequate RVV supply were identified as some of the enablers of RVV coverage. Conclusion: Few broad recommendations to overcome identified barriers include comprehensive inter-sectoral coordination, regular monitoring and frequent refresher training sessions. There is a need for a future study utilizing existing coverage data and larger sample size to triangulate the findings of this study.

Digitizing tools for post introduction evaluation of rotavirus vaccine introduction in India.

Background and aims: The Rotavirus vaccine (RVV) introduction is a landmark event in the history of Indian public health as for the first time a novel, low-cost indigenous vaccine was introduced in a short timeline between 2016 and 2019. As per WHO mandate, post-introduction evaluation (PIE) be conducted within 6 to 12 months of vaccine introduction to provide an understanding of the operational aspects of the program. For RVV PIE, an innovative approach to developing and deploying a digitized tool was employed. The present study aims to document the processes followed for digitizing the data collection and analysis tools. Methods: The development of the RVV-PIE digital tool was undertaken in two phases. In the first phase, conceptualization and iteration of the modified WHO PIE tool were undertaken. Questions were organized sequentially to ensure natural progression in responses. The finalized questionnaire was converted to a digital version and extensive dummy data was entered to improve automated qualitative data analysis. Phase 2 involved updating the draft tool and incorporating changes to provide a field-tested version for deployment. Results: The digital version of the tool was successfully developed. The GPS functionality of the tool allowed live tracking of data collection making the process more accountable. The tool was prepopulated with reference materials and data points for easy reference and retrieval by the evaluators. The digitization of the tool also allowed easy visualization of data through maps, charts, and graphs on a real-time user-friendly dashboard. Conclusions: The digitization of the PIE tool for RVV in India has been a great learning experience where the dire situation of an ongoing pandemic catapulted us towards a more efficient and comprehensive process innovation. The RVV PIE tool could serve as a customizable digital PIE tool for other health programs heralding an era of a more effective and proficient process of PIE.

Benefits of thermal and distance-filtered imaging for wayfinding with prosthetic vision.

Visual prostheses such as the Argus II provide partial vision for individuals with limited or no light perception. However, their effectiveness in daily life situations is limited by scene complexity and variability. We investigated whether additional image processing techniques could improve mobility performance in everyday indoor environments. A mobile system connected to the Argus II provided thermal or distance-filtered video stimulation. Four participants used the thermal camera to locate a person and the distance filter to navigate a hallway with obstacles. The thermal camera allowed for finding a target person in 99% of trials, while unfiltered video led to confusion with other objects and a success rate of only 55% ([Formula: see text]). Similarly, the distance filter enabled participants to detect and avoid 88% of obstacles by removing background clutter, whereas unfiltered video resulted in a detection rate of only 10% ([Formula: see text]). For any given elapsed time, the success rate with filtered video was higher than with unfiltered video. After 90 s, participants' success rate reached above 50% with filtered video and 24% and 3% with normal camera in the first and second tasks, respectively. Despite individual variations, all participants showed significant improvement when using the thermal and distance filters compared to unfiltered video. Adding a thermal and distance filter to a visual prosthesis system can enhance the performance of mobility activities by removing clutter in the background, showing people and warm objects with the thermal camera, or nearby obstacles with the distance filter.

Wrapper-based deep feature optimization for activity recognition in the wearable sensor networks of healthcare systems.

The Human Activity Recognition (HAR) problem leverages pattern recognition to classify physical human activities as they are captured by several sensor modalities. Remote monitoring of an individual's activities has gained importance due to the reduction in travel and physical activities during the pandemic. Research on HAR enables one person to either remotely monitor or recognize another person's activity via the ubiquitous mobile device or by using sensor-based Internet of Things (IoT). Our proposed work focuses on the accurate classification of daily human activities from both accelerometer and gyroscope sensor data after converting into spectrogram images. The feature extraction process follows by leveraging the pre-trained weights of two popular and efficient transfer learning convolutional neural network models. Finally, a wrapper-based feature selection method has been employed for selecting the optimal feature subset that both reduces the training time and improves the final classification performance. The proposed HAR model has been tested on the three benchmark datasets namely, HARTH, KU-HAR and HuGaDB and has achieved 88.89%, 97.97% and 93.82% respectively on these datasets. It is to be noted that the proposed HAR model achieves an improvement of about 21%, 20% and 6% in the overall classification accuracies while utilizing only 52%, 45% and 60% of the original feature set for HuGaDB, KU-HAR and HARTH datasets respectively. This proves the effectiveness of our proposed wrapper-based feature selection HAR methodology.

Enablers and Barriers to the Scaling Up of Pneumococcal Conjugate Vaccine in India During the COVID-19 Pandemic: A Qualitative Study.

Background: Pneumonia is one of the leading causes of death in under-5 children in India. This led the Ministry of Health & Family Welfare (MoHFW) in India to decide for the nationwide roll-out of the Pneumococcal Conjugate Vaccine (PCV). However, the introduction of PCV became more complex in the face of unprecedented challenges set forth by the COVID-19 pandemic. The study aims to assess enablers and barriers to the introduction of PCV in India during the pandemic. Methodology: Qualitative research approach involving key-informant interviews from John Snow India (JSI), the lead technical agency that supported MoHFW in the PCV expansion was employed to delineate the enablers and barriers. Principle of saturation was employed to derive the sample size. Thematic analysis using inductive approach was based on the modified World Health Organization (WHO) framework for new vaccine introduction impact on the Immunization and Health Systems, using NVIVO 12 qualitative data analysis software. Results: A total of 11 key informants (4 national-level program managers and 7 state technical officers) were telephonically interviewed. The study found social acceptance, lower cost of the vaccine, and intensive communication activities as potential enablers. Other enablers for PCV introduction included a robust vaccine supply-chain system, ample cold-chain space availability, and strong political commitment, despite the ongoing second wave. Further, the identified barriers included poor physical access, insufficient social mobilization, and limited advocacy along with a stretched workforce. Conclusion: The study delineated several enablers and barriers to introducing PCV in the country during the pandemic. The existing barriers in the PCV roll-out prompted the need to address these gaps, making key program-based recommendations to improve future new vaccine introductions during the pandemic.

Development of a Choice-framework for Covid vaccines in India using a multi-criteria decision analysis approach.

BACKGROUND: Vaccines were crucial in controlling the Covid-19 pandemic. As more vaccines receive regulatory approval, stakeholders will be faced with several options and must make an appropriate choice for themselves. We proposed a multi-criteria decision analysis (MCDA) framework to guide decision-makers in comparing vaccines for the Indian context. METHODS: We adhered to the ISPOR guidance for the MCDA process. Seven vaccine options were compared under ten criteria. Through three virtual workshops, we obtained opinions and weights from citizens, private-sector hospitals, and public health organisations. Available evidence was rescaled and incorporated into the performance matrix. The final score for each vaccine was calculated for the different groups. We performed different sensitivity analyses to assess the consistency of the rank list. RESULTS: The cost, efficacy and operational score of the vaccines had the highest weights among the stakeholders. From the six scenario groups, Janssen had the highest score in four. This was driven by the advantage of having a single dose of vaccination. In the probabilistic sensitivity analysis for the overall group, Covaxin, Janssen, and Sputnik were the first three options. The participants expressed that availability, WHO approvals and safety, among others, would be crucial when considering vaccines. CONCLUSIONS: The MCDA process has not been capitalised on in healthcare decision-making in India and LMICs. Considering the available data and stakeholder preference at the time of the study, Covaxin, Janssen, and Sputnik were preferred options. The choice framework with the dynamic performance matrix is a valuable tool that could be adapted to different population groups and extended based on increasing vaccine options and emerging evidence. *ISPOR - The Professional Society for Health Economics and Outcomes Research.

Critical factors in the successful expansion of Pneumococcal Conjugate Vaccine in India during the COVID-19 pandemic.

India had decided to roll out PCV in India in 2015, but successful implementation of any new vaccine introduction mandates an enormous effort. PCV was scaled up during the COVID-19 pandemic, which posed new, unprecedented challenges in the vaccine rollout. However, India successfully expanded PCV in the country in record time across all states and Union Territories. During the pandemic, supply-side restrictions, delayed vaccine shipments, staff shortages, and restrictions in conducting training negatively affected the roll-out of PCV across the country. However, despite the ongoing pandemic, India successfully rolled out PCV across the country in 7 months. In this review, the authors have conducted a narrative review to delineate the crucial factors that helped in the successful expansion of PCV.

Using new cold chain technologies to extend the vaccine cold chain in India: Equipment performance, acceptability, systems fit, and costs.

This study evaluated the performance, acceptability, costs, and systems fit of three new cold chain devices in India: a second-generation ice-lined refrigerator (ILR), a solar direct drive (SDD) refrigerator, and a long-term passive device (LTPD). The evaluation was conducted over 15 months during 2016-2017. Sites were selected for their diversity in climate, terrain, and grid electrical supply, and 31 cold chain devices were deployed, 1 to each site. Results showed that all three technologies maintained correct temperatures. The SDD refrigerators had no malfunctions, whilst the ILRs had at least one malfunction, mostly due to the printed circuit board's sensitivity to the erratic power supply. The LTPD temperature display panel caused challenges initially that required replacement of all solar panels with lithium batteries. Yet the devices' long holdovers helped ensure vaccine potency. One challenge, particularly with the ILRs and SDD refrigerators, was condensation. The passively cooled LTPD was valued in settings with smaller populations and unreliable or no power; however, some its features, including the need to condition ice blocks, made it challenging to operate. In addition, the acceptable temperature range for the LTPD, as for all passively cooled devices (greater than 0 °C and less than + 10 °C), was confusing for some health workers due to the decades-long emphasis on maintaining temperatures at + 2 °C to + 8 °C. The greatest system-related benefit was establishment of new cold chain points (CCPs) at locations with intermittent or no grid electricity, bringing immunisation services closer to hard-to-reach areas. A key limitation of all three devices was the inability to freeze ice packs, which are required for vaccine carriers, somewhat restricting the potential of these technologies to reach underserved populations. Moreover, establishing new CCPs added costs to the health system. Results from this study, including costing data, can help guide decision-making.

Diagnostic accuracy of RBC scintigraphy and CTA for detection of patients with suspected lower gastrointestinal bleeding: a systematic review and meta-analysis.

OBJECTIVE: Detection of lower gastrointestinal bleeding (LGIB) through noninvasive modalities is very important in the successful management of LGIB. RBC scintigraphy and CT have a role in the detection of LGIB and guiding the management of patient by localization of the bleeding site. However, only a small number of studies have evaluated the role of RBC scintigraphy and CT in the diagnosis of LGIB. This systematic review was conducted to evaluate the diagnostic performance of RBC scintigraphy and CT in the detection of LGIB in patients with clinical or biochemical findings suspicious of LGIB. METHODS: This systematic review followed PRISMA guidelines. Searches in PubMed, Scopus, and Embase were conducted using relevant keywords, and articles published through 30 April 2022, were included. Using endoscopy or surgical outcomes as the reference standard, the numbers of true and false positives and true and false negatives were extracted. Pooled estimates of diagnostic test accuracy - including sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and summary ROC (SROC) curve - were generated using bivariate random-effects meta-analysis. RESULTS: Three studies comprising 171 patients were included in the systematic review and meta-analysis. The pooled sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio for the detection of LGIB using RBC scintigraphy were 0.787 (95% CI, 0.643-0.893), 0.289 (95% CI, 0.164-0.443), 1.214 (95% CI, 0.923-1.597) and 0.576 (95% CI, 0.296-1.121) respectively. The area under the SROC curve was 0.73. The pooled sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio for the detection of LGIB using CT were 0.931 (95% CI, 0.772-0.992), 0.870 (95% CI, 0.737-0.951), 6.085 (95% CI, 0.840-44.097), 0.126 (95% CI, 0.006-2.509) respectively. The area under the SROC curve was 0.095. CONCLUSION: RBC scintigraphy has overall good sensitivity and CTA has excellent sensitivity specificity, positive and negative likelihood ratio in the detection of LGIB in patients with clinical or biochemical findings suspicious for LGIB.CTA along with RBC scintigraphy can be used algorithmically to rule out patients who do not have a localization for the site of LGIB thereby helping these patients to avoid invasive procedures like endoscopy or surgical explorations.

An exploratory simulation study and prediction model on human brain behavior and activity using an integration of deep neural network and biosensor Rabi antenna.

The plasmonic antenna probe is constructed using a silver rod embedded in a modified Mach-Zehnder interferometer (MZI) ad-drop filter. Rabi antennas are formed when space-time control reaches two levels of system oscillation and can be used as human brain sensor probes. Photonic neural networks are designed using brain-Rabi antenna communication, and transmissions are connected via neurons. Communication signals are carried by electron spin (up and down) and adjustable Rabi frequency. Hidden variables and deep brain signals can be obtained by external detection. A Rabi antenna has been developed by simulation using computer simulation technology (CST) software. Additionally, a communication device has been developed that uses the Optiwave program with Finite-Difference Time-Domain (OptiFDTD). The output signal is plotted using the MATLAB program with the parameters of the OptiFDTD simulation results. The proposed antenna oscillates in the frequency range of 192 THz to 202 THz with a maximum gain of 22.4 dBi. The sensitivity of the sensor is calculated along with the result of electron spin and applied to form a human brain connection. Moreover, intelligent machine learning algorithms are proposed to identify high-quality transmissions and predict the behavior of transmissions in the near future. During the process, a root mean square error (RMSE) of 2.3332(±0.2338) was obtained. Finally, it can be said that our proposed model can efficiently predict human mind, thoughts, behavior as well as action/reaction, which can be greatly helpful in the diagnosis of various neuro-degenerative/psychological diseases (such as Alzheimer's, dementia, etc.) and for security purposes.

Advances in hybrid peptide-based self-assembly systems and their applications.

Self-assembly of peptides demonstrates a great potential for designing highly ordered, finely tailored supramolecular arrangements enriched with high specificity, improved efficacy and biological activity. Along with natural peptides, hybrid peptide systems composed of natural and chemically diverse unnatural amino acids have been used in various fields, including drug delivery, wound healing, potent inhibition of diseases, and prevention of biomaterial related diseases to name a few. In this review, we provide a brief outline of various methods that have been utilized for obtaining fascinating structures that create an avenue to reproduce a range of functions resulting from these folds. An overview of different self-assembled structures as well as their applications will also be provided. We believe that this review is very relevant to the current scenario and will cover conformations of hybrid peptides and resulting self-assemblies from the late 20th century through 2022. This review aims to be a comprehensive and reliable account of the hybrid peptide-based self-assembly owing to its enormous influence in understanding and mimicking biological processes.

Conformationally rigid aromatic amino acids as potential building blocks for abiotic foldamers.

This communication describes the development of conformationally constrained unnatural aromatic amino acids, constructed on rigid backbone wherein the carboxyl and amino groups project in two dimensions (planes) on the aromatic framework. Such a feature offers the possibility of design and development of conformationally ordered synthetic oligomers with intriguing structural architectures distinct from those classically observed. Furthermore, such amino acids will have the potential to extend the conformational space available for foldamer design with diverse backbone conformation and structural architectures.

Glow in the dark: Using a heat-sensitive camera for blind individuals with prosthetic vision.

To date, retinal implants are the only available treatment for blind individuals with retinal degenerations such as retinitis pigmentosa. Argus II is the only visual implant with FDA approval, with more than 300 users worldwide. Argus II stimulation is based on a grayscale image coming from a head-mounted visible-light camera. Normally, the 11°×19° field of view of the Argus II user is full of objects that may elicit similar phosphenes. The prosthesis cannot meaningfully convey so much visual information, and the percept is reduced to an ambiguous impression of light. This study is aimed at investigating the efficacy of simplifying the video input in real-time using a heat-sensitive camera. Data were acquired from four Argus II users in 5 stationary tasks with either hot objects or human targets as stimuli. All tasks were of m-alternative forced choice design where precisely one of the m≥2 response alternatives was defined to be "correct" by the experimenter. To compare performance with heat-sensitive and normal cameras across all tasks, regardless of m, we used an extension of signal detection theory to latent variables, estimating person ability and item difficulty in d' units. Results demonstrate that subject performance was significantly better across all tasks with the thermal camera compared to the regular Argus II camera. The future addition of thermal imaging to devices with very poor spatial resolution may have significant real-life benefits for orientation, personal safety, and social interactions, thereby improving quality of life.

Eye movements and the perceived location of phosphenes generated by intracranial primary visual cortex stimulation in the blind.

BACKGROUND: Restoring sight for the blind using electrical stimulation of the visual pathways is feasible but demands an understanding of the spatial mapping of the visual world at the site of targeted stimulation, whether in the retina, thalamus, or cortex. While a visual cortex stimulator can bypass the eye and create visual percepts, there is an inherent dissociation between this stimulation and eye movements. It is unknown whether and how robustly the brain maintains the oculomotor circuitry in patients with bare- or no-light perception. OBJECTIVE: To critically and quantitatively evaluate the effect of eye movements have on phosphene locations elicited by cortical stimulation that bypasses the eyes in order to restore sight in blind subjects. METHODS: The NeuroPace Responsive Neurostimulator (RNS) and the Orion visual cortical prosthesis devices were used to electrically stimulate the visual cortex of blind subjects with bare or no light perception. Eye positions were recorded synchronized with stimulation and the location of the percepts were measured using a handheld marker. RESULTS: The locations of cortical stimulation-evoked percepts are shifted based on the eye position at the time of stimulation. Measured responses can be remapped based on measured eye positions to determine the retinotopic locations associated with the implanted electrodes, with remapped responses having variance limited by pointing error. CONCLUSIONS: Eye movements dominate the perceived location of cortical stimulation-evoked phosphenes, even after years of blindness. By accounting for eye positions, we can mimic retinal mapping as in natural sight.