Long wavelength mid-infrared multi-gases spectroscopy using tunable single-mode slot waveguide quantum cascade laser.

Single-mode tunable quantum cascade lasers (QCLs) are promising for high-resolution and highly sensitive trace gases sensing across the mid-infrared (MIR) region. We report on the development of a tunable single-mode slot waveguide QCL array in the long wavelength part of the MIR regime (>12 µm). This laser array exhibits a tuning range of around 12 cm-1, from 735.3 to 747.3 cm-1. Using this developed single-mode tunable QCL, we demonstrate individual gas sensing, yielding the detection limit of 940 ppb and 470 ppb for acetylene and o-xylene, respectively. To verify the potential of the developed QCL array in multi-species gas detection, laser absorption measurements of two mixed gases of acetylene and o-xylene were conducted, showing the absorption features of the corresponding gases agree well with the theoretical predictions.

Widely tunable single-mode slot waveguide quantum cascade laser array.

We report designs and experimental demonstrations of a widely tunable single-mode quantum cascade laser array based on slot waveguide structures in the mid-infrared region. The laser array device realized a continuous tuning range of 71 cm-1 from 9.66 µm to 10.37 µm at 300 K only using the current tuning without any external heatsink temperature adjustments, in good agreement with the design. Stable single-mode operations free of undesired mode-hops have been obtained over the whole tuning range. Another slot waveguide QCL array with a 41 cm-1 continuous tuning range around 7.3 µm has also been realized with the same design principle, demonstrating the universal applicability of the array design. The broadly continuous tuning with simple processing makes the array device a suitable candidate for mid-infrared sensing and spectroscopy application.

Beam combining of a broadly and continuously tunable quantum cascade laser.

We report a cost-efficient method to demonstrate the beam combining of five laser elements in an array of tunable slot waveguide quantum cascade lasers in the mid-infrared region at around 10 µm. An aspherical lens with five fine-tuned mini mirrors was employed to collimate the individual beams from the laser array. To verify the feasibility of this beam combining approach, the combined beams were coupled into a hollow-core fiber gas cell with a low numerical aperture (N.A.) of 0.03 and a coupling efficiency >= 0.82, for gas sensing of binary compound gases of ammonia and ethylene simultaneously.

High body mass index and sleep problems during pregnancy: A meta-analysis and meta-regression of observational studies.

Despite the well-established correlation of weight and sleeping problems, little is known about the nature of the association. The present study examined whether pregnant women with high body mass index have a risk of developing sleep problems, and identified any covariates that affect this relationship. We systematically searched electronic databases, specialized journals, various clinical trial registries, grey literature databases and the reference list of the identified studies. All observational studies were obtained from inception until 9 August 2020. The Newcastle-Ottawa Scale was adopted to assess the quality of studies. Stata software was used to conduct meta-analysis and meta-regression. Forty-six observational studies involving 2,240,804 participants across 16 countries were included. Quality assessment scores ranged from 4 to 10 (median = 6). Meta-analyses revealed that the risk of sleep apnea, habitual snoring, short sleep duration and poor sleep quality is increased in pregnant women with high body mass index, but not for daytime sleepiness, insomnia or restless legs syndrome. Subgroup differences were detected on body mass index between different regions, nature of population, year of publication, age group and study quality. Random-effects meta-regression analyses showed that year and quality of publication were covariates on the relationships between pre-pregnant body mass index and sleep apnea risk. Our review shows that sleep apnea, habitual snoring, short sleep duration and poor sleep quality are important concerns for pregnant women with high body mass index. Developing screening and targeted interventions is recommended to promote efficacious perinatal care.

High-performance InGaAs/InAlAs single-photon avalanche diode with a triple-mesa structure for near-infrared photon detection.

We present a novel, to the best of our knowledge, InGaAs/InAlAs single-photon avalanche diode (SPAD) with a triple-mesa structure. Compared with the traditional mesa structures, the horizontal distribution of the electric field decreases dramatically, while the peaks of the electric field at the mesa edges are well eliminated in the triple-mesa structure, leading to an excellent suppression of the surface leakage current and premature breakdown. Furthermore, the temperature coefficient of the breakdown voltage was measured to be as small as 37.4 mV/K within a range from 150 to 270 K. Eventually, one of the highest single-photon detection efficiencies of 35% among all the InGaAs/InAlAs SPADs with a decent dark count rate of ${3.3} \times {{10}^7}\;{\rm Hz}$ was achieved at 240 K. Combined with the inherent ease of integration of the mesa structure, this high-performance triple-mesa InGaAs/InAlAs SPAD provides an effective solution for the fabrication of SPAD arrays and the on-chip integration of quantum systems.

Use of Green Solvents in Metallaphotoredox Cross-Electrophile Coupling Reactions Utilizing a Lipophilic Modified Dual Ir/Ni Catalyst System.

Facilitating photoredox coupling reactions in process-friendly green solvents was achieved by the successful application of a dual Ir/Ni catalyst system with enhanced solubility properties. These photochemical reactions (specifically Br-Br sp2-sp3 cross electrophile coupling) are reported in a head to head comparison to the standard di-t-Bu bipyridine ligand Ir/Ni catalyst system. This presentation highlights the benefits of altering the solubility properties of the ligands used in the Ir/Ni dual catalyst.

Integration of an InSb photodetector on Si via heteroepitaxy for the mid-infrared wavelength region.

In this study, InSb p-i-n photodetectors with In0.82Al0.18Sb barrier layers were grown on a (100) 6° offcut Si substrate by heteroepitaxy via an AlSb/GaSb buffer. Based on an interfacial misfit array growth mode, the dislocations at the GaSb/Si and InSb/AlSb interfaces accommodated the lattice mismatch. The In0.82Al0.18Sb barrier layer increased the 77 K R0A of the detector. From 180 K to 300 K, the generation-recombination mechanism dominated the dark current generation in the detector and surface leakage became dominant below 120 K. The detector exhibited a 77 K responsivity of 0.475 A/W and a Johnson-noise-limited detectivity of 3.08 × 109 cmHz1/2W-1 at 5.3 µm.

Normal variation in sagittal spinal alignment parameters in adult patients: an EOS study using serial imaging.

PURPOSE: To describe normal variations in sagittal spinal radiographic parameters over an interval period and establish physiological norms and guidelines for which these images should be interpreted. METHODS: Data were prospectively collected from a continuous series of adult patients with first-episode mild low back pain presenting to a single institution. The sagittal parameters of two serial radiographic images taken 6-months apart were obtained with the EOS® slot scanner. Measured parameters include CL, TK, TL, LL, PI, PT, SS, and end and apical vertebrae. Chi-squared test and Wilcoxon Signed Rank test were used to compare categorical and continuous variables, respectively. RESULTS: Sixty patients with a total of 120 whole-body sagittal X-rays were analysed. Mean age was 52.1 years (SD 21.2). Mean interval between the first and second X-rays was 126.2 days (SD 47.2). Small variations (< 1°) occur for all except PT (1.2°), CL (1.2°), and SVA (2.9 cm). Pelvic tilt showed significant difference between two images (p = 0.035). Subgroup analysis based on the time interval between X-rays, and between the first and second X-rays, did not show significant differences. Consistent findings were found for end and apical vertebrae of the thoracic and lumbar spine between the first and second X-rays for sagittal curve shapes. CONCLUSIONS: Radiographic sagittal parameters vary between serial images and reflect dynamism in spinal balancing. SVA and PT are predisposed to the widest variation. SVA has the largest variation between individuals of low pelvic tilt. Therefore, interpretation of these parameters should be patient specific and relies on trends rather than a one-time assessment.

Inverting Conventional Chemoselectivity in Pd-Catalyzed Amine Arylations with Multiply Halogenated Pyridines.

A new catalyst system capable of selective chloride functionalization in the Pd-catalyzed amination of 3,2- and 5,2- Br/Cl-pyridines is reported. A reaction optimization strategy employing ligand parametrization led to the identification of 1,1'-bis[bis(dimethylamino)phosphino]ferrocene "DMAPF", a readily available yet previously unutilized diphosphine, as a uniquely effective ligand for this transformation.

Comparison of Local Recurrence After Simple and Skin-Sparing Mastectomy Performed in Patients with Ductal Carcinoma In Situ.

BACKGROUND: The incidence of ductal carcinoma in situ (DCIS) is increasing with the use of screening mammography, and approximately 30% of all women diagnosed with DCIS are treated by mastectomy. There is increasing use of a skin-sparing mastectomy (SSM) approach to surgically excise DCIS as this facilitates immediate breast reconstruction. The rates of locoregional recurrence (LRR) after simple mastectomy performed for pure DCIS are historically reported as 1%; however, international data suggest that LRR after SSM may be higher. METHODS: To determine our rates of LRR and compare the effect of the type of mastectomy performed, we undertook a retrospective review of all patients who underwent a mastectomy for pure DCIS at our institution between 2000 and 2010. RESULTS: In total, 199 patients underwent a mastectomy for pure DCIS (with eight local recurrences), all of which were invasive ductal carcinoma. The recurrences all occurred after SSM, which was associated with a higher 5-year LRR of 5.9% (5/102) compared with 0% in the simple mastectomy group (0/97; p = 0.012), log-rank. Univariate analysis showed the two factors that predicted the risk of recurrence were a young age at mastectomy and close or involved margins. CONCLUSIONS: These data highlight the importance of achieving clear margins, especially in young women with estrogen receptor-negative DCIS who have a higher risk of invasive recurrence. Women undergoing a mastectomy for DCIS should be counseled as to the importance of achieving clear margins and the potential increased need for further excision, post-mastectomy radiotherapy and post-reconstruction mammography in order to prevent LRR after SSM.

Integration of InGaAs MOSFETs and GaAs/ AlGaAs lasers on Si Substrate for advanced opto-electronic integrated circuits (OEICs).

Lasers monolithically integrated with high speed MOSFETs on the silicon (Si) substrate could be a key to realize low cost, low power, and high speed opto-electronic integrated circuits (OEICs). In this paper, we report the monolithic integration of InGaAs channel transistors with electrically pumped GaAs/AlGaAs lasers on the Si substrate for future advanced OEICs. The laser and transistor layers were grown on the Si substrate by molecular beam epitaxy (MBE) using direct epitaxial growth. InGaAs n-FETs with an ION/IOFF ratio of more than 106 with very low off-state leakage and a low subthreshold swing with a minimum of 82 mV/decade were realized. Electrically pumped GaAs/AlGaAs quantum well (QW) lasers with a lasing wavelength of 795 nm at room temperature were demonstrated. The overall fabrication process has a low thermal budget of no more than 400 °C.

Monolithic integration of InGaAs n-FETs and lasers on Ge substrate.

We report the first monolithic integration of InGaAs channel field-effect transistors with InGaAs/GaAs multiple quantum wells (MQWs) lasers on a common platform, achieving a milestone in the path of enabling low power and high speed opto-electronic integrated circuits (OEICs). The III-V layers used for realizing transistors and lasers were grown epitaxially on the Ge substrate using molecular beam epitaxy (MBE). A Si-CMOS compatible process was developed to realize InGaAs n-FETs with subthreshold swing SS of 93 mV/decade, ION/IOFF ratio of more than 4 orders of magnitude with very low off-state leakage current, and a peak effective mobility of more than 2000 cm2/V·s. In addition, fabrication process uses a low overall processing temperature (≤ 400 °C) to maintain the high quality of the InGaAs/GaAs MQWs for the laser. Room temperature electrically-pumped lasers with a lasing wavelength of 1.03 µm and a linewidth of less than 1.7 nm were realized.

Multidimensional Treatment of Cancer Pain.

PURPOSE OF REVIEW: Though numerous treatment options are available to address cancer pain, inadequate management continues to be an ongoing problem worldwide. RECENT FINDINGS: A systematic review of the recent scientific literature was conducted with attention to new therapies along with reports of general consensus that were analyzed. Pain research continues to be difficult and though numerous guidelines have been developed, adequate powered studies are not common. Good practice would suggest a comprehensive approach to cancer pain management taking into account the many options available and treating each patient with a personalized therapeutic program. Though there is a very low number of randomized control trials, this probably reflects the difficulty in conducting these studies in heterogeneous cancer pain patient populations in sufficient numbers to yield credible study power.

Identification, synthesis and evaluation of SARS-CoV and MERS-CoV 3C-like protease inhibitors.

Severe acute respiratory syndrome (SARS) led to a life-threatening form of atypical pneumonia in late 2002. Following that, Middle East Respiratory Syndrome (MERS-CoV) has recently emerged, killing about 36% of patients infected globally, mainly in Saudi Arabia and South Korea. Based on a scaffold we reported for inhibiting neuraminidase (NA), we synthesized the analogues and identified compounds with low micromolar inhibitory activity against 3CL(pro) of SARS-CoV and MERS-CoV. Docking studies show that a carboxylate present at either R(1) or R(4) destabilizes the oxyanion hole in the 3CL(pro). Interestingly, 3f, 3g and 3m could inhibit both NA and 3CL(pro) and serve as a starting point to develop broad-spectrum antiviral agents.

Management of Early Node-Positive Breast Cancer in Australia: A Multicentre Study.

To examine practice patterns for breast cancer patients with limited sentinel node (SN) disease in light of the ACOSOG Z0011 results. Retrospective analysis of patients with T1-2 breast cancer and positive sentinel lymph node biopsy (SLNB) admitted between January 2009 and December 2012. Patient demographics, tumor characteristics, and treatments were recorded. Eight hundred positive SLNBs were identified. A total of 452 (56.5%) proceeded to completion axillary lymph node dissection (cALND). cALND rate decreased from 65.1% to 49.7% from 2009-2010 to 2011-2012. cALND was performed for micrometastasis or isolated tumor cells in 39.3% in 2009-2010 and 22.2% in 2011-2012, whereas for macrometastases the rates were 83.1% and 68.6%, respectively. cALND rates diminished for both Z0011-eligible and -ineligible patients. The ACOSOG Z0011 trial presentation and publication coincided with a reduction in cALND for breast cancer with limited nodal disease. There appears equipoise regarding management of macrometastatic SN disease.

Parents are poor at labelling wheeze in children: a cross-sectional study.

BACKGROUND: Noisy breathing is a common presenting symptom in children. The purpose of this study is to (a) assess parental ability to label wheeze, (b) compare the ability of parents of children with and without asthma to label wheeze and (c) determine factors affecting parental ability to label wheeze correctly. METHODS: This cross-sectional study in a tertiary hospital in Kuala Lumpur, Malaysia involved parents of children with asthma. Parents of children without asthma were the control group. Eleven validated video clips showing wheeze, stridor, transmitted noises, snoring or normal breathing were shown to the parents. Parents were asked, in English or Malay, "What do you call the sound this child is making?" and "Where do you think the sound is coming from?" RESULTS: Two hundred parents participated in this study: 100 had children with asthma while 100 did not. Most (71.5 %) answered in Malay. Only 38.5 % of parents correctly labelled wheeze. Parents were significantly better at locating than labelling wheeze (OR 2.4, 95 % CI 1.64-3.73). Parents with asthmatic children were not better at labelling wheeze than those without asthma (OR1.04, 95 % CI 0.59-1.84). Answering in English (OR 3.4, 95 % CI 1.69-7.14) and having older children with asthma (OR 9.09, 95 % CI 3.13-26.32) were associated with correct labelling of wheeze. Other sounds were mislabelled as wheeze by 16.5 % of respondents. CONCLUSION: Parental labelling of wheeze was inaccurate especially in the Malay language. Parents were better at identifying the origin of wheeze rather than labelling it. Physicians should be wary about parental reporting of wheeze as it may be inaccurate.

Distal-selective hydroformylation using scaffolding catalysis.

In hydroformylation, phosphorus-based directing groups have been consistently successful at placing the aldehyde on the carbon proximal to the directing group. The design and synthesis of a novel catalytic directing group are reported that promotes aldehyde formation on the carbon distal relative to the directing functionality. This scaffolding ligand, which operates through a reversible covalent bond to the substrate, has been applied to the diastereoselective hydroformylation of homoallylic alcohols to afford δ-lactones selectively. Altering the distance between the alcohol and the olefin revealed that homoallylic alcohols gives the distal lactone with the highest levels of regioselectivity.

Internalized Sexual Stigma and Mental Health Outcomes for Gay, Lesbian, and Bisexual Asian Americans: The Moderating Role of Guilt and Shame.

The literature unequivocally demonstrates that lesbian, gay, and bisexual (LGB) individuals experience disproportionate mental health and social wellbeing impacts. Here, we respond to recent calls for research in the field of sexual minority health to better understand why various overlapping and intersecting identities can further drive health disparities. In this paper, we focus on the specific intersections of ethnicity and sexuality for Asian LGB individuals and the role of internalized stigma in driving poorer mental health outcomes for this group. We recruited 148 LGB Asian participants residing in the United States (Mage = 22.82 years, SD = 4.88) to participate in our online cross-sectional survey in which we collected data on their internalized stigma, levels of guilt and shame about their sexuality, and measures of depression, anxiety, and distress. Contrary to our predictions, there were no bivariate relationships between internalized sexual stigma and any of the mental health outcomes. However, a parallel mediation analysis revealed that guilt, but not shame, mediates the relationship between internalized sexual stigma and all mental health outcomes (depression, anxiety, and stress) for LGB Asian American individuals. This research highlights the important of exploring additional variables that may exacerbate of protect against poor mental health for individuals with multiple intersecting identities.

Kern's six-step approach allows for meaningful implementation of an orthognathic surgery training course.

OBJECTIVES: This study investigated the effectiveness of simulation training in improving the confidence and competency of oral and maxillofacial surgery (OMS) residents in performing orthognathic surgery (OGS). METHODS: Kern's six-step approach was applied when designing the simulation training for OMS residents. The difficulties encountered by the residents when learning OGS were considered when designing the training program. A training course consisting of didactic sessions, hands-on training on three-dimensional training models, and an assessment tool was implemented for OMS residents. Improvement in the confidence and competence of OMS residents in performing OGS, fidelity of the three-dimensional models, and satisfaction with the course was evaluated. RESULTS: All OMS residents (10/10) completed the course. The perceived difficulty in learning OGS was mainly related to the manipulation of the jawbones. While there were improvements in the median confidence and competence scores (3/5 to 4/5), only the differences in competence were found to be statistically significant (p < 0.01, Wilcoxon signed-rank test). Improvements in confidence and competence did not correlate. The mean fidelity scores of both the maxillary and mandibular models were adequate at 3.2 out of 5. Overall, satisfaction with the course was high (5/5). CONCLUSIONS: The six-step approach provides a guided process for educators to formulate a training course directed toward the perceived needs of students. Targeted training can significantly enhance the students' competence. Greater efforts should also be put in place to allow simultaneous developments in the students' confidence along with their competence.

Experiences of body image in the gender non-binary community: A qualitative analysis.

Body image concerns are prevalent within transgender communities - many transgender people engage in disordered eating to suppress or accentuate secondary sex characteristics and reduce gender dysphoria. However, this research has mostly been conducted with binary transgender people. Here, we examine how non-binary people experience and relate to their bodies. Semi-structured one-on-one interviews were conducted with 13 gender non-binary individuals living in Australia. Photo elicitation techniques were utilised, and the transcribed interview data were analysed using reflexive thematic analysis. Six themes were identified: Expansive Understandings of Body Image, Body Image can be Linked to Gender Dysphoria, Cultivating a Preferred Body can Lead to Gender Euphoria, Appreciating Diversity in Non-Binary Body Ideals, The Androgynous Body Ideal is not Universally Accepted, and Experiencing the Body as Functional rather than Aesthetic. The present findings highlight the diversity of experiences of body image for non-binary people. The non-binary concept of body image was found to be expansive, stressing various physical attributes involved in social gender recognition and physiological sources of gender dysphoria. Some participants valued gender-affirming medical intervention, others were accepting of their bodies as they are, attributing their body confidence to the process of affirming their non-binary gender.