In Silico Peptide Repertoire of Human Olfactory Receptor Proteomes on High-Stringency Mass Spectrometry

Human olfactory receptors (ORs) are seven-pass transmembrane G-protein coupled receptors (GPCR) involved in smell perception and many other signaling pathways. They are primarily expressed in the olfactory epithelium and ectopically expressed in several other organs and tissues. neXtProt contains 4 PE1 (protein existence 1, evidenced at the protein level) ORs, determined on the basis of either protein interaction data (i.e., OR1D4 and OR2AG1) or convincing genetic, haplotype, or biochemical data (i.e., OR1D2 and OR2J3). Not a single OR currently qualifies for neXtProt PE1 status based on mass spectrometry (MS) evidence. Many reasons for this absence of MS-based identification have been proposed, including (i) confined or spatiotemporal or developmental expression, (ii) low copy number, (iii) OR repertoire gene silencing, and (iv) limited tissue availability. OR transmembrane domains (TMDs) inherently limit MS identification because the hydrophobic nature restricts the access of trypsin to potential cleavage sites. Equally, the extremely low frequency or lack of accessible arginine and lysine residues in TMDs renders trypsin cleavage ineffective. Here, we demonstrate an analytical approach specifically focused on the hydrophilic (trypsin-accessible) domains of ORs [i.e., with all transmembrane segments and anchored peptides excluded). We predicted the ability of OR soluble (hydrophilic) domains to yield 2 or more >9 amino acids (aa) length unique mapping (unique to a protein only), non-nested (peptides with varying length at the N or C terminal but containing the same core sequence), leucine/isoleucine (I/L) switch examined (I and L have same mass and cannot be distinguished by MS) tryptic peptides. Our analysis showed that ∼58% of the human OR proteome could potentially generate tryptic peptides that satisfy current the Human Proteome Project data interpretation guidelines (version 2.1) when no missed cleavages are allowed and increases to ∼78% when one missed cleavage is allowed. The utilization of current biological data (adjuvant genomics, expression profile, transcriptomics, epigenome silencing data, etc.) and the adoption of a non-conventional proteomics approach (e.g., Confetti multiprotease digestion, CNBr cleavage of TMDs, and more-extreme chromatographic and MS methods) could aid in the detection of the remaining ORs.

Direct Observation of Proton-Neutron Short-Range Correlation Dominance in Heavy Nuclei

We measured the triple coincidence A(e,e^{'}np) and A(e,e^{'}pp) reactions on carbon, aluminum, iron, and lead targets at Q^{2}>1.5  (GeV/c)^{2}, x_{B}>1.1 and missing momentum >400  MeV/c. This was the first direct measurement of both proton-proton (pp) and neutron-proton (np) short-range correlated (SRC) pair knockout from heavy asymmetric nuclei. For all measured nuclei, the average proton-proton (pp) to neutron-proton (np) reduced cross-section ratio is about 6%, in agreement with previous indirect measurements. Correcting for single-charge exchange effects decreased the SRC pairs ratio to ∼3%, which is lower than previous results. Comparisons to theoretical generalized contact formalism (GCF) cross-section calculations show good agreement using both phenomenological and chiral nucleon-nucleon potentials, favoring a lower pp to np pair ratio. The ability of the GCF calculation to describe the experimental data using either phenomenological or chiral potentials suggests possible reduction of scale and scheme dependence in cross-section ratios. Our results also support the high-resolution description of high-momentum states being predominantly due to nucleons in SRC pairs.

First Measurements of the Double-Polarization Observables F, P, and H in ω Photoproduction off Transversely Polarized Protons in the N^{*} Resonance Region

First measurements of double-polarization observables in ω photoproduction off the proton are presented using transverse target polarization and data from the CEBAF Large Acceptance Spectrometer (CLAS) FROST experiment at Jefferson Lab. The beam-target asymmetry F has been measured using circularly polarized, tagged photons in the energy range 1200-2700 MeV, and the beam-target asymmetries H and P have been measured using linearly polarized, tagged photons in the energy range 1200-2000 MeV. These measurements significantly increase the database on polarization observables. The results are included in two partial-wave analyses and reveal significant contributions from several nucleon (N^{*}) resonances. In particular, contributions from new N^{*} resonances listed in the Review of Particle Properties are observed, which aid in reaching the goal of mapping out the nucleon resonance spectrum.

Slowdown in Antarctic mass loss from solid Earth and sea-level feedbacks

Geodetic investigations of crustal motions in the Amundsen Sea sector of West Antarctica and models of ice-sheet evolution in the past 10,000 years have recently highlighted the stabilizing role of solid-Earth uplift on polar ice sheets. One critical aspect, however, that has not been assessed is the impact of short-wavelength uplift generated by the solid-Earth response to unloading over short time scales close to ice-sheet grounding lines (areas where the ice becomes afloat). Here, we present a new global simulation of Antarctic evolution at high spatiotemporal resolution that captures all solid Earth processes that affect ice sheets and show a projected negative feedback in grounding line migration of 38% for Thwaites Glacier 350 years in the future, or 26.8% reduction in corresponding sea-level contribution.

Minimizing Trap Charge Density towards an Ideal Diode in Graphene-Silicon Schottky Solar Cell

Photovoltaic device performance of graphene/n-Si Schottky diodes is largely affected by inhomogeneous oxide formation at the interface that suppresses the tunneling current of injected and photoexcited charges. The accumulated trap charges at low current induce charge recombination at the interface and degrade the ideality factor of the diode and the fill factor (FF) of the solar cell. This consequently gives rise to a nonlinear current-voltage ( I- V) feature in solar cells, commonly known as an S-shaped kink, which can be engineered by optimizing the interface barrier thickness or by increasing the carrier mobility. Here, we present chemical and electrochemical doping methods to increase the conductivity of graphene that transforms nonlinear kink photodiodes with a low FF and solar cell efficiency towards trap-free linear photovoltaic I- V. Space-charge-limited-current manifested Ohmic I- V diode behavior with enhanced conductance in graphene by injecting homogeneous ionic liquid; confirming the significant reduction of trap charge density. This was further congruent with the disappearance of the nonlinear kink in photodiodes with a high FF and nearly ideal diodes. The solar cell efficiency obtained with our strategy is around 13.6% and suggests possibilities to reach the theoretical limit of 19% by tailoring parameters such as conductance of graphene, carrier density of Si, and oxidation of the interfaces.

Center of Mass Motion of Short-Range Correlated Nucleon Pairs studied via the A(e,e^{'}pp) Reaction

Short-range correlated (SRC) nucleon pairs are a vital part of the nucleus, accounting for almost all nucleons with momentum greater than the Fermi momentum (k_{F}). A fundamental characteristic of SRC pairs is having large relative momenta as compared to k_{F}, and smaller center of mass (c.m.) which indicates a small separation distance between the nucleons in the pair. Determining the c.m. momentum distribution of SRC pairs is essential for understanding their formation process. We report here on the extraction of the c.m. motion of proton-proton (pp) SRC pairs in carbon and, for the first time in heavier and ansymetric nuclei: aluminum, iron, and lead, from measurements of the A(e,e^{'}pp) reaction. We find that the pair c.m. motion for these nuclei can be described by a three-dimensional Gaussian with a narrow width ranging from 140 to 170  MeV/c, approximately consistent with the sum of two mean-field nucleon momenta. Comparison with calculations appears to show that the SRC pairs are formed from mean-field nucleons in specific quantum states.

Pediatric endocrine society survey of diabetes practices in the United States: What is the current state?

BACKGROUND

The Practice Management Committee (PMC) of the Pediatric Endocrine Society (PES) conducted a survey of its membership in February/March, 2016 to assess the current state of pediatric diabetes care delivery across multiple practice types in the United States.

METHODS

The PES distributed an anonymous electronic survey (Survey Monkey) via email to its membership and requested that only one survey be completed for each practice.

RESULTS

Ninety-three unique entries from the US were entered into analysis. Care is predominantly delivered by multidisciplinary teams, based at academic institutions (65.6%), with >85% of the provider types being physicians. Each 1.0 full time equivalent certified diabetes educators serves on average 367 diabetic youth. Fee-for-service remains the standard method of reimbursement with 57% of practices reporting financial loss. Survey respondents identified under-reimbursement as a major barrier to improving patient outcomes and lack of behavioral health (BH) providers as a key gap in services provided.

CONCLUSIONS

Our survey reveals wide variation in all aspects of pediatric diabetes care delivery in the United States. Pediatric Endocrinologists responding to the survey identified a lack of resources and the current fee for service payment model as a major impediment to practice and the lack of integrated BH staff as a key gap in service. The respondents strongly support its organizations' involvement in the dissemination of standards for care delivery and advocacy for a national payment model aligned with chronic diabetes care in the context of our emerging value-based healthcare system.

Assessment of Periodontal Status of the People in Chepang Hill Tract of Nepal: A Cross Sectional Study

Background Periodontal disease is one of the common oral and dental disease globally. The main etiology of periodontal disease is microbial plaque. However, it shares many common etiological factors with other chronic diseases. The Chepang are an indigenous TibetoBurman people group numbering around fifty-two thousand mainly inhabiting the rugged ridges of the Mahabharat mountain range of central Nepal. They are the tribes with different food habit, religion and culture. Till date no studies has been conducted about the periodontal and oral health status of the Chepang people. Objective To determine the prevalence of periodontitis in adult Chepang population so that knowing about its prevalence and distribution, besides serving as a demographic tool, will also help in having overview about the need for providing proper oral health care and awareness programs and initiatives aimed at reducing the disease prevalence in this indigenous group. Method The study was conducted among the adult (21 to 70 years) Chepang of Chitwan district. It was the cross sectional study with the random sampling technique. Modified Community Periodontal Index (CPI) and loss of attachment were used to record the periodontal status of all 308 sampled population. Result Out of 308 sampled participants 179 were male and 129 were female. The highest number of participants were from 41 to 50 years old (38.31%). 57.14% adult Chepang brushes their teeth once daily and 31.49% brushes twice daily and 1.30% of them had never brushes their teeth. 36.36% had loss of attachment of 4-5 mm without any significant gender difference. 6.17% of the study population had severe form of periodontitis with ≥ 12 mm of attachment loss. Calculus deposit was abundant in 57.79% of the study sample, and 25.64% shows pocket depth of 4 to 5 mm. Loss of attachment and CPI score is found to be increased with increasing age. Conclusion Result of this study reveals the presence of periodontal problems in adult Chepang population. Higher calculus with attachment loss and pocket depth were the major problems seen in this community. This highlights the necessity of implementation of more preventive program in this specific targeted population.

Probing the shear modulus of two-dimensional multiplanar nanostructures and heterostructures

Generalized high-fidelity closed-form formulae have been developed to predict the shear modulus of hexagonal graphene-like monolayer nanostructures and nano-heterostructures based on a physically insightful analytical approach. Hexagonal nano-structural forms (top view) are common for nanomaterials with monoplanar (such as graphene and hBN) and multiplanar (such as stanene and MoS₂) configurations. However, a single-layer nanomaterial may not possess a particular property adequately, or multiple desired properties simultaneously. Recently, a new trend has emerged to develop nano-heterostructures by assembling multiple monolayers of different nanostructures to achieve various tunable desired properties simultaneously. Shear modulus assumes an important role in characterizing the applicability of different two-dimensional nanomaterials and heterostructures in various nanoelectromechanical systems such as determining the resonance frequency of vibration modes involving torsion, wrinkling and rippling behavior of two-dimensional materials. We have developed mechanics-based closed-form formulae for the shear modulus of monolayer nanostructures and multi-layer nano-heterostructures. New results of shear modulus are presented for different classes of nanostructures (graphene, hBN, stanene and MoS₂) and nano-heterostructures (graphene-hBN, graphene-MoS₂, graphene-stanene and stanene-MoS₂), which are categorized on the basis of fundamental structural configurations. The numerical values of shear modulus are compared with the results from the scientific literature (as available) and separate molecular dynamics simulations, wherein a good agreement is noticed. The proposed analytical expressions will enable the scientific community to efficiently evaluate shear modulus of a wide range of nanostructures and nanoheterostructures.

Measurement of the Q^{2} Dependence of the Deuteron Spin Structure Function g_{1} and its Moments at Low Q^{2} with CLAS

We measured the g_{1} spin structure function of the deuteron at low Q^{2}, where QCD can be approximated with chiral perturbation theory (χPT). The data cover the resonance region, up to an invariant mass of W≈1.9  GeV. The generalized Gerasimov-Drell-Hearn sum, the moment Γ_{1}^{d} and the spin polarizability γ_{0}^{d} are precisely determined down to a minimum Q^{2} of 0.02  GeV^{2} for the first time, about 2.5 times lower than that of previous data. We compare them to several χPT calculations and models. These results are the first in a program of benchmark measurements of polarization observables in the χPT domain.

Effective mechanical properties of multilayer nano-heterostructures

Two-dimensional and quasi-two-dimensional materials are important nanostructures because of their exciting electronic, optical, thermal, chemical and mechanical properties. However, a single-layer nanomaterial may not possess a particular property adequately, or multiple desired properties simultaneously. Recently a new trend has emerged to develop nano-heterostructures by assembling multiple monolayers of different nanostructures to achieve various tunable desired properties simultaneously. For example, transition metal dichalcogenides such as MoS₂ show promising electronic and piezoelectric properties, but their low mechanical strength is a constraint for practical applications. This barrier can be mitigated by considering graphene-MoS₂ heterostructure, as graphene possesses strong mechanical properties. We have developed efficient closed-form expressions for the equivalent elastic properties of such multi-layer hexagonal nano-hetrostructures. Based on these physics-based analytical formulae, mechanical properties are investigated for different heterostructures such as graphene-MoS₂, graphene-hBN, graphene-stanene and stanene-MoS₂. The proposed formulae will enable efficient characterization of mechanical properties in developing a wide range of application-specific nano-heterostructures.

First Exclusive Measurement of Deeply Virtual Compton Scattering off ^{4}He: Toward the 3D Tomography of Nuclei

We report on the first measurement of the beam-spin asymmetry in the exclusive process of coherent deeply virtual Compton scattering off a nucleus. The experiment uses the 6 GeV electron beam from the Continuous Electron Beam Accelerator Facility (CEBAF) accelerator at Jefferson Lab incident on a pressurized ^{4}He gaseous target placed in front of the CEBAF Large Acceptance Spectrometer (CLAS). The scattered electron is detected by CLAS and the photon by a dedicated electromagnetic calorimeter at forward angles. To ensure the exclusivity of the process, a specially designed radial time projection chamber is used to detect the recoiling ^{4}He nuclei. We measure beam-spin asymmetries larger than those observed on the free proton in the same kinematic domain. From these, we are able to extract, in a model-independent way, the real and imaginary parts of the only ^{4}He Compton form factor, H_{A}. This first measurement of coherent deeply virtual Compton scattering on the ^{4}He nucleus, with a fully exclusive final state via nuclear recoil tagging, leads the way toward 3D imaging of the partonic structure of nuclei.

A High-On/Off-Ratio Floating-Gate Memristor Array on a Flexible Substrate via CVD-Grown Large-Area 2D Layer Stacking

Memristors such as phase-change memory and resistive memory have been proposed to emulate the synaptic activities in neuromorphic systems. However, the low reliability of these types of memories is their biggest challenge for commercialization. Here, a highly reliable memristor array using floating-gate memory operated by two terminals (source and drain) using van der Waals layered materials is demonstrated. Centimeter-scale samples (1.5 cm × 1.5 cm) of MoS₂ as a channel and graphene as a trap layer grown by chemical vapor deposition (CVD) are used for array fabrication with Al₂ O₃ as the tunneling barrier. With regard to the memory characteristics, 93% of the devices exhibit an on/off ratio of over 10³ with an average ratio of 10⁴ . The high on/off ratio and reliable endurance in the devices allow stable 6-level memory applications. The devices also exhibit excellent memory durability over 8000 cycles with a negligible shift in the threshold voltage and on-current, which is a significant improvement over other types of memristors. In addition, the devices can be strained up to 1% by fabricating on a flexible substrate. This demonstration opens a practical route for next-generation electronics with CVD-grown van der Waals layered materials.

Charge Transport in MoS2/WSe2 van der Waals Heterostructure with Tunable Inversion Layer

Despite numerous studies on two-dimensional van der Waals heterostructures, a full understanding of the charge transport and photoinduced current mechanisms in these structures, in particular, associated with charge depletion/inversion layers at the interface remains elusive. Here, we investigate transport properties of a prototype multilayer MoS₂/WSe₂ heterojunction via a tunable charge inversion/depletion layer. A charge inversion layer was constructed at the surface of WSe₂ due to its relatively low doping concentration compared to that of MoS₂, which can be tuned by the back-gate bias. The depletion region was limited within a few nanometers in the MoS₂ side, while charges are fully depleted on the whole WSe₂ side, which are determined by Raman spectroscopy and transport measurements. Charge transport through the heterojunction was influenced by the presence of the inversion layer and involves two regimes of tunneling and recombination. Furthermore, photocurrent measurements clearly revealed recombination and space-charge-limited behaviors, similar to those of the heterostructures built from organic semiconductors. This contributes to research of various other types of heterostructures and can be further applied for electronic and optoelectronic devices.

Postoperative Analgesic Effect of Morphine Added to Bupivacaine for Transversus Abdominis Plane (TAP) Block in Appendectomy

Background Transversus abdominis plane (TAP) block with local anaesthetics produces effective pain relief following lower abdominal surgeries. Although opioids have been found to have effects through peripheral receptors also, reports on their effect when used as additive to local anaesthetics for TAP block are lacking. Objective To assess the analgesic effect of peripherally administered morphine with bupivacaine for ipsilateral TAP block in patients undergoing emergency appendectomy under general anaesthesia. Method Sixty patients undergoing appendectomy were randomized to undergo ipsilateral TAP with 20 ml of 0.5% bupivacaine plus 2 ml of NS (total 22 ml) and 2 ml of intravenous (IV) saline (Group TB) or with 20ml of 0.5% bupivacaine plus 2 mg (2 ml) of morphine (total 22 ml) and 2 ml of NS IV (Group TBM) or with 20 ml of 0.5% bupivacaine plus 2 ml of NS (total 22 ml) and 2 mg (2 ml) IV morphine (Group TB-IVM). Pain severity was measured using Visual Analogue Scale (VAS) preoperatively (Baseline) and at 30 min, 6h, 12 h and 24 h postoperatively. Inj. tramadol 50 mg IV was used as rescue analgesic when postoperative VAS was 4 or more. The duration of analgesia (time to first analgesic) and the postoperative 24 h tramadol requirement was recorded. Result The mean duration of analgesia in Group TBM was significantly longer (801.50 ± 74.92 min, p=0.002) than in Group TB (720.00 ± 42.17 min) and Group TB-IVM (712.70 ± 40.94 min). The mean postoperative 24 h tramadol requirement was also less in Group TBM (69.23 ± 25.31mg) than in Groups TB (100.00 ± 38.34 mg) and TB-IVM (95.00 ± 39.40 mg) but did not reach the level of statistical significance (p=0.057). Significantly less ondansetron was required in Group TBM (3.80 ± 2.04 mg) than in Group TB (6.80 ± 2.93 mg) and TB-IVM (6.00 ± 2.75 mg) (p=0.002). Conclusion Morphine added to bupivacaine effectively prolongs the analgesic duration of TAP block in appendectomy.

Photocurrent Switching of Monolayer MoS2 Using a Metal-Insulator Transition

We achieve switching on/off the photocurrent of monolayer molybdenum disulfide (MoS₂) by controlling the metal-insulator transition (MIT). N-type semiconducting MoS₂ under a large negative gate bias generates a photocurrent attributed to the increase of excess carriers in the conduction band by optical excitation. However, under a large positive gate bias, a phase shift from semiconducting to metallic MoS₂ is caused, and the photocurrent by excess carriers in the conduction band induced by the laser disappears due to enhanced electron-electron scattering. Thus, no photocurrent is detected in metallic MoS₂. Our results indicate that the photocurrent of MoS₂ can be switched on/off by appropriately controlling the MIT transition by means of gate bias.

3D-SISPROT: A simple and integrated spintip-based protein digestion and three-dimensional peptide fractionation technology for deep proteome profiling

Multidimensional peptide fractionation strategies have been approved as the efficient approaches to significantly improve the depth of proteome coverage. In this study, a simple and integrated spintip-based protein digestion and three-dimensional peptide fractionation technology (3D-SISPROT) was developed for the deep proteome profiling from low microgram of proteins as starting materials. All the sample preparation steps, including protein digestion, strong anion exchange (SAX)-based fractionation, and high-pH reversed phase (RP) fractionation were integrated into one pipette tip packed with SAX and C₁₈ membranes for the first time. The SAX plus C₁₈ membranes design minimizes the sample loss and ensures high efficient SAX-based digestion. 4275 proteins were identified with 1.4h of MS time when 6μg cell lysates was processed. More importantly, the SAX-based digestion procedure did not influence the SAX-based peptide fractionation efficiency which was done in the same SAX membrane. The 3D-SISPROT was exemplified by the analysis of 30μg of HEK 293T cell lysates with 20.4h of MS time, which resulted in the identification of 8222 proteins including 3215 annotated membrane proteins. Gene Ontology annotations indicated that the 3D-SISPROT was unbiased for the proteins from major cellular components. Taking advantages of the efficient SAX-based and high-pH RP-based fractionation strategies, we expect that the 3D-SISPROT can be applied for the deep proteome profiling with limited starting material.

Factors Associated with Smokeless Tobacco Use among Pregnant Women in Rural Areas of the Southern Terai, Nepal

BACKGROUND

Tobacco use among women during pregnancy leading to poor maternal and child health outcomes has been well documented. However, factors influencing use of smokeless tobacco in Nepal has not yet been well established. This study aims at exploring the factors related to smokeless tobacco use among pregnant women in rural southern Terai of Nepal.

METHODS

A community-based cross-sectional study was performed at 52 wards within 6 Village Development Committee in Dhanusha district of Nepal. A total of 426 expectant mothers in their second trimester were selected using a multistage cluster sampling method. Descriptive and regression analyses were done to explore the factors that influence smokeless tobacco use.

RESULTS

In a total of 426 pregnant mothers, one in five used tobacco in any form. Among the users, 13.4% used smokeless tobacco. Pregnant mothers who were smoking tobacco (AOR 6.01; 95% CI (1.88-19.23), having alcohol consumption (AOR 3.86; 95% CI (1.23-12.08), stressed (AOR 5.04; 95% CI (1.81-14.03), non-vegetarian (AOR 3.31;(1.84-13.03), not attending regular mothers' group meetings (AOR 4.63; (1.41-15.19), and not-exposed to mass media (AOR 5.02; (1.89-13.33) were significantly associated with smokeless tobacco use. Similarly, mothers of age group 20-34 years, dalit, aadibasi and janajati, hill origin, no education and primary education were more likely to use smokeless tobacco than their counterparts.

CONCLUSIONS

Factors such as smoking tobacco, alcohol consumption, stress, and poor education were found to be significantly associated with smokeless tobacco use among pregnant women in southern Terai of Nepal. This requires an immediate attention develop an effective strategy to prevent and control smokeless tobacco use among pregnant women in southern Terai of Nepal.

Determining the Fermi level by absorption quenching of monolayer graphene by charge transfer doping

While optical properties of graphene in the visible region are solely defined by the frequency-independent fine structure constant, an onset of absorption has been observed in the infrared region due to Pauli blocking of interband transitions. Here, we report a complete absorption quenching in the infrared region by coating graphene with bis(trifluoromethanesulfonyl)amine (TFSA), an optically transparent p-type chemical dopant. The Fermi level downshift due to TFSA doping results in enhanced transmission in the infrared region proportional to the doping concentration. An absorption quenching onset method, developed in our work, to extract the Fermi level shift in pristine and doped graphene agrees with values extracted from Raman G-band and 2D-band shifts, Hall measurements and the binding energy shift observed in X-ray photo-electron spectroscopy. Performing simple UV-visible transmittance spectroscopy to obtain the absorption quenching onset of graphene also allows detection of environmental and substrate effects via Fermi level shift. Our method opens up the practical implementation of this unique phenomenon of graphene in future optoelectronic devices.