Here, we present a highly sensitive and fast hydrogen (H-2) sensor for 1% H-2, well below the critical limit of explosion ignite in air, in a temperature range of 28-150 degrees C by using monolayer MoS2 pyramid structures with enhanced adsorption sites. The monolayer MoS2 pyramid structures is synthesized by modified chemical vapor deposition technique and characterized by field emission scanning electron microscopy, Raman, photoluminescence and atomic force microscopy. The highest sensitivity of 69.1% was achieved at a moderate and atomic force microscopy. The highest sensitivity of 69.1% was achieved at a moderate temperature with a response time of 32.9 s for the monolayer MoS2 pyramid structures. At room temperature (RT), the sensor showed a sensitivity of 6% with a faster response of 11.3 s and recovery time of 125.3 s. The availability of favourable adsorption sites on in-plane MoS(2)and edges of MoS2 in monolayer MoS(2 )structures provide enhanced adsorption sites for gas sensing and resulted in the high sensitivity and low response time sensing mechanism is proposed in the light of detail surface morphology and density function theory (DFT). This study reveals that tailoring the favourable adsorption sites in 2D materials is helpful to develop the highly sensitive and fast H-2 sensor for next generation safety devices for H-2 fueled vehicle and clean energy applications. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Background Vitamin D (VitD) has been shown to have anti-fibrotic properties in the bleomycin mouse model of pulmonary fibrosis. This study aimed to establish whether an association exists between VitD deficiency and outcomes in patients with idiopathic pulmonary fibrosis (IPF). Methods The VitD status of an anti-fibrotic treated IPF patient cohort at a single UK tertiary centre was retrospectively analysed. Clinical deficiency was defined as VitD<25 nmol/L as per NICE guidelines. Serial lung function was determined in the 12 months (or as close as possible) after the VitD test. Frequency of infections and acute exacerbation events were recorded, and transplant-free survival was calculated from the earliest patient contact. Results Of 300 IPF patients, 92 (30.6%) had documented VitD results (78.3% male, mean age 72±8 years). Sixteen (17.4%) patients were clinically deficient. Baseline FVC and DLco were 70.3%±11.9% and 39.1%±12.9% in the non-deficient and 68.4%±10.7% and 39.8%±8.8% in the deficient groups respectively (p=0.55, p=0.85 respectively). There was no significant difference in the prevalence of VitD deficiency between patients taking Pirfenidone (11/66 (17%)) and Nintedanib (5/26 (19%))(p=0.77). Median transplant-free survival was 1128 days in the non-deficient group and 532 days in the deficient group (p=0.0079)(Figure 1). Following adjustment for age, gender and baseline composite physiologic index (CPI), the Cox proportional hazard ratio for VitD deficiency and transplant-free survival was 2.36 (95% CI 1.128–4.942, p=0.023). There was no difference in mean annual relative change in FVC between deficient (-8.0%±8.9%) and non-deficient patients (-9.1% ±12.9%)(p=0.79). The incidence of infections and acute exacerbations did not significantly differ between groups. Conclusions In this cohort of antifibrotic treated IPF patients, there is an association between VitD deficiency and adverse outcomes. Whether VitD deficiency is associated with a poorer prognosis as a surrogate for a co-morbid state or is relevant to IPF disease pathogenesis remains unclear. Although limited by cohort size, it is curious that reduced survival appears to be independent of lung function decline and further analyses with regard aetiology of mortality is required. Prospective studies of VitD supplementation in antifibrotic treated IPF patients may be indicated to explore a potential therapeutic role.

We report the experimental demonstration of an all-optical, bias free and error-free (biterror-rate ~10-12), 10Gbit/s non-return-to-zero (NRZ) to return-to-zero (RZ) data format conversion in a 7.5μm diameter III-V microdisk integrated on top of a silicon-on-insulator (SOI) waveguide circuit.

We give an overview of our work in the field of heterogeneously integrated III-V-on-silicon photonic integrated circuits for communication and sensing applications.

A novel ultracompact electro-optic phase modulator based on a single 9 μm-diameter III-V microdisk resonator heterogeneously integrated on and coupled to a nanophotonic waveguide is presented. Modulation is enabled by effective index modification through carrier injection. Proof-of-concept implementation involving binary phase shift keying modulation format is assembled. A power imbalance of ∼0.6  dB between both symbols and a modulation rate up to 1.8 Gbps are demonstrated without using any special driving technique.

In this paper, we demonstrate excitability in a silicon-on-insulator microring. Neglecting the fast light dynamics simplifies the calculation of the excitability onset. Excitable microrings will be useful as a basic building block in all-optical neural networks.

We describe progress in the design and fabrication of laser diodes based on InP-membranes heterogeneously integrated onto silicon-on-insulator wire waveguides. Applications in optical interconnect and all-optical logic are discussed.

The heterogeneous integration of III-V semiconductor lasers on a silicon waveguide platform using DVS-BCB adhesive bonding is reviewed. Both mW-level lasers and ultra-compact laser sources are discussed.

By employing optical injection-locking the direct modulation bandwidth of a 10μm diameter disc laser is increased to 15GHz. In addition, modulation at 20Gb/s is demonstrated with only 1mW DC bias & 190mV data signals (50fJ/bit).

Using InP-based microdisk lasers heterogeneously integrated onto silicon passive waveguide circuits, we demonstrate all-optical wavelength conversion of 10Gbps NRZ PRBS signals without requiring any bias or extra seeding beam. The experimental results also indicate that bitrates of 20 or 25Gbps should be achievable.

Using thin membrane InP microdisc lasers heterogeneously integrated on a silicon on insulator (SOI) substrate having a broadband analogue modulation bandwidth of 11 GHz, analogue direct modulation with radio data signals (64 and 256 QAM, 20M symbols/s at 5 GHz RF carrier) is demonstrated. The demonstration shows the potential of the microdisc laser as a low-energy analogue optical transmitter with error-vector magnitude penalties of 3.6 and 4.2% for 64 and 256 QAM, respectively, and the low biasing currents for both DC (4 mW) and RF (0.1 mW) signals, which are compatible with signals and currents which can be supplied by a simple CMOS driving chip.

Microdisc lasers (MDLs) are an attractive option for on-chip laser sources, wavelength converters and all-optical memory. We have developed a comprehensive model for MDL flip-flops and numerically investigate their switching properties in comparison with experiments.

We demonstrate flip-flop operation using the directional bistability in ultra-small microdisks (7.5 μm diameter) heterogeneously bonded on a silicon chip. The pulse energies are only 1.8 fJ and the bias current is 3.5 mA.

We give proof of concept demonstrations for the use of a single InP membrane disc structure as both a directly modulated light source and photo-detector using a 27 -1 PRBS sequence at rates up to 10 Gb/s.

HISTORIC aims to develop and test complex photonic integrated circuits containing a relatively large number of digital photonic elements for use in e.g. all-optical packet switching. These photonic digital units are all-optical flip-flops based on ultra compact laser diodes, such as microdisk lasers and photonic crystal lasers. These lasers are fabricated making use of the heterogeneous integration of InP membranes on top of silicon on insulator (SOI) passive optical circuits. The very small dimensions of the lasers are, at least for some approaches, possible because of the high index contrast of the InP membranes and by making use of the extreme accuracy of CMOS processing. All-optical flip-flops based on heterogeneously integrated microdisk lasers with diameter of 7.5μm have already been demonstrated. They operate with a CW power consumption of a few mW and can switch in 60ps with switching energies as low as 1.8 fJ. Their operation as all-optical gate has also been demonstrated. Work is also on-going to fabricate heterogeneously integrated photonic crystal lasers and all-optical flip-flops based on such lasers. A lot of attention is given to the electrical pumping of the membrane InP-based photonic crystal lasers and to the coupling to SOI wire waveguides. Optically pumped photonic crystal lasers coupled to SOI wires have been demonstrated already. The all-optical flip-flops and gates will be combined into more complex photonic integrated circuits, implementing all-optical shift registers, D flip-flops, and other all-optical switching building blocks. The possibility to integrate a large number of photonic digital units together, but also to integrate them with compact passive optical routers such as AWGs, opens new perspectives for the design of integrated optical processors or optical buffers. The project therefore also focuses on designing new architectures for such optical processing or buffer chips.

Using a 7.5 mu m wide InP Micro-Disc-Laser, with a very low similar to 100 mu A threshold current, heterogeneously integrated on top of Silicon on Insulator substrate, all optical NRZ wavelength conversion at speeds up to 20Gb/s is demonstrated (C) 2009 Optical Society of America

We demonstrate the use of heterogeneously integrated microdisk lasers for application in low-power and high-speed all-optical flip-flops and gates. Flip-flop operation is experimentally demonstrated using pulse energies of 1.8 fJ in lasers with a diameter of 7.5 μm. Potential optimization of the performance and future photonic integrated circuits are also described. Keywordsmicrodisk laser, heterogeneous integration, digital photonics

Pain following any surgical procedure is difficult to combat by man. Analgesics can be given for some amount of symptomatic relief. The need for a long lasting local anaesthetic is with the intention to reduce the most severe nature of pain, and decrease the analgesic consumption. This study was conducted to compare the efficacy of, Bupivacaine over Lidocaine for minor oral surgical procedures. The popularly used lidocaine works for 3 to 3.9 hours. This is not sufficient since the most severe nature of pain is felt six to eight hours post surgery, where as Bupivacaine has duration of action of seven to eight hours. Hence the post operative pain experienced following administration of bupivacaine was found to be considerably lesser in degree than compared to the lidocaine group. To avoid severe pain and discomfort to the patient following any minor oral surgical, the use of bupivacaine is recommended.

A cross-sectional survey was carried out to study the dynamics of contraceptive use in three villages of Raipur Rani block in district Panchkula, Haryana. A female social worker interviewed 600 ever-married women aged 15-44 years using a semi-structured interview schedule. More than 75% of the respondents were aware about modern contraceptives. Fifty-nine percent of the couples had used contraceptives. Among the 351 ever-users, the first contraceptive method used was sterilization in 41.3%, condom in 35.6%, IUD in 17.9%, and oral pills in 5.1%. Subsequently, many of them either discontinued or shifted to other methods. At the time of survey, 236 (39.3%) were using a contraceptive. Most of the current users (225) had opted for tubectomy, and only a few (4) had accepted vasectomy. Supplies of contraceptives were obtained mainly from government hospitals and sub-health centres. Common reasons for discontinuation were perceived untoward effects (37.1%), desire for more children (32.6%), and failure of the contraceptive method (19.0%). Most of the respondents obtained contraceptives from Government health posts. Counselling and follow-up services should should be strengthened so that contraceptives are used regularly and effectively for longer periods.