bluuebunny/crossref_metadata_2025 huggingface dataset:
Boundary-Layer Solution for a Flow in a Diverging Passage Having a Swirl Component
Authors: Sinbel M. A.
Published: June 2021

In this paper a solution is given to estimate the boundary-layer thickness owing to translational and rotational motion. The solution is an attempt to derive the boundary-layer equations when the main stream possesses both swirl and axial velocity. The development of the boundary layer in a conical duct is influenced by centrifugal action in addition to the pressure and viscous forces. The boundary-layer momentum integral equations are derived and presented herein for a set of spherical polar co-ordinates. The solution has been carried out for laminar flow. A turbulent form of the solution can be obtained by the introduction of the mixing-length theory. A numerical solution is carried out to make a comparison between the estimated and actual measured values.
Thermal Stresses Owing to a Hot Spot in a Rectangular Strip
Authors: Nelson C. W.
Published: June 2021

The thermal stresses for the plane-stress problem of a circular hot spot in an infinitely long straight strip of rectangular cross section are derived by a Fourier integral approach. The hot spot is located on the longitudinal center line of the strip, and its radius is such that the boundary of the hot spot is tangent to both edges of the strip. The temperature may be any function of the radius within the hot spot and is assumed to have a constant value (zero) throughout the rest of the strip. Numerical values are given for the stresses on the edges and both center lines of the strip for a particular case.
Axially Symmetric Extensional Vibrations of a Circular Disk With a Concentric Hole
Authors: Gustafsson O. G. , Kane T. R.
Published: June 2021

In a paper by T. R. Kane and R. D. Mindlin, a two-dimensional theory was developed for high-frequency extensional vibrations of elastic, isotropic plates. This theory is now used to study vibrations of a circular disk with a concentric hole.
Carrying Capacity of Elastic-Plastic Shells With Various End Conditions, Under Hydrostatic Compression
Authors: Paul Burton
Published: June 2021

This paper considers the influence of the beam-column effect on the carrying capacity of hydrostatically loaded elastic-plastic cylindrical shells. Specific problems considered include shells with clamped ends, simply supported ends, and a combination thereof. It is shown that in all cases considered there exist two characteristic modes of failure corresponding, respectively, to long and short shells where the terms “long” and “short” are unambiguously defined. Detailed results are presented graphically along with general conclusions useful for design purposes.
Incremental Stress-Strain Law Applied to Work-Hardening Plastic Materials
Authors: Hwang Chintsun
Published: June 2021

For problems involving work-hardening plastic materials, the incremental stress-strain law is considered to be a more rational approach than the conventional total stress-strain law. Up to the present the incremental stress-strain law was not subject to widespread use because it is mathematically inconvenient to handle. In this paper a method is developed in which the incremental law is applied to a work-hardening material in plane stress corresponding to the yield condition of von Mises. The method is illustrated by an analysis of the plastic bending of a simply supported work-hardening circular plate under uniformly distributed transverse load. The resulting difference-differential equations are solved by the NCR 304 digital computer.
On the Plastic Flow of Coulomb Solids Beyond Original Failure
Authors: Jenike A. W. , Shield R. T.
Published: June 2021

Principles developed for rigid-plastic solids exhibiting Coulomb’s properties are adapted to the analysis of flow beyond original failure. A variable yield function is proposed to account for the changes of cohesion during flow and equations are evolved for the stress field in two dimensions. It is shown that, while in the stress field an effective angle of friction larger than the actual angle of friction is mandatory for these materials, in the velocity field the materials can be assumed incompressible.
Piping Flexibility Analysis by Stiffness Matrix
Authors: Chen L. H.
Published: June 2021

A method of analysis is formalized for the solution of thermal-expansion stress problems in piping systems. The method is particularly suited for a complex system involving many anchors, closed loops within loops and/or interconnecting branch lines but without intermediate partial constraints. A summary of formulas and procedures necessary for practical application is included in the Appendix. Emphasis has been placed on the simplicity of the procedures which are well suited for automatic computation in digital computers.
The Fundamental Frequency of a Thin, Flat, Circular Plate Simply Supported Along a Circle of Arbitrary Radius
Authors: Bodine R. Y.
Published: June 2021

The fundamental transverse frequency is determined for a thin, flat, circular plate simply supported along a circle of arbitrary radius. It is shown that there are three support locations which coincide with “classical” plate solutions. The dimensionless frequency is plotted against the ratio of the support radius and outer-edge radius, showing the frequency variation with support location. The maximum frequency occurs when the support is located at the diameter of the first nodal circle of a free-edge plate.
Principal Component Analysis of Knee Joint Differences Between Bilateral and Unilateral Total Knee Replacement Patients During Level Walking
Authors: Yocum Derek , Reinbolt Jeffrey , Weinhandl Joshua T. , Standifird Tyler W. , Fitzhugh Eugene , Cates Harold , Zhang Songning
Published: June 2021

Many unilateral total knee replacement (TKR) patients will need a contralateral TKR. Differences in knee joint biomechanics between bilateral patients and unilateral patients are not well established. The purpose of this study was to examine knee joint differences in level walking between bilateral and unilateral patients, and asymptomatic controls, using principal component analysis. Knee joints of 1st replaced limbs of 15 bilateral patients (69.40 ± 5.04 years), 15 replaced limbs of unilateral patients (66.47 ± 6.15 years), and 15 asymptomatic controls (63.53 ± 9.50 years) were analyzed during level walking. Principal component analysis examined knee joint sagittal- and frontal-plane kinematics and moments, and vertical ground reaction force (GRF). A one-way analysis of variance analyzed differences between principal component scores of each group. TKR patients exhibited more flexed and abducted knees throughout stance, decreased sagittal knee range of motion (ROM), increased early-stance adduction ROM, decreased loading-response knee extension and push-off knee flexion moments, decreased loading-response and push-off peak knee abduction moment (KAbM), increased KAbM at midstance, increased midstance vertical GRF, and decreased loading-response and push-off vertical GRF. Additionally, bilateral patients exhibited reduced sagittal knee ROM, increased adduction ROM, decreased sagittal knee moments throughout stance, decreased KAbM throughout stance, an earlier loading-response peak vertical GRF, and a decreased push-off vertical GRF, compared to unilateral patients. TKR patients, especially bilateral patients had stiff knee motion in the sagittal-plane, increased frontal-plane joint laxity, and a quadriceps avoidance gait.
Adiabatic Effectiveness and Thermal Field Measurements of a Shaped Hole in the Showerhead of a Model Turbine Blade
Authors: Moore Jacob D. , Horner Matthew J. , Bogard David G.
Published: June 2021

Few published studies incorporating shaped hole designs in the leading-edge region, or showerhead, of turbine airfoils have been performed; but among them is the indication that shaped holes may offer an improvement in coolant performance compared to cylindrical holes. A shaped hole was designed with the goal of high performance in the showerhead. The performance and physical behavior of this shaped hole design was studied in comparison to a traditional cylindrical hole design in a series of experiments. The geometries were built into the leading edge of a scaled-up turbine blade model for testing in a low-speed simulated linear cascade. To accomplish an engine-representative test environment, a nominally 5% approach turbulence level was used for this study. Adiabatic effectiveness as a function of coolant injection rate was measured for the two designs using infrared thermography. In addition, off-the-wall thermal field measurements were performed for each hole geometry in the leading-edge region. It was found that the shaped hole offered ∼20 − 100% higher performance in terms of adiabatic effectiveness depending on the coolant injection rate. The thermal field measurements suggested that this was due to the better attachment of the jets exiting the shaped holes, the momenta of which were effectively reduced by the diffusers.
Sociology of Sport: Growth, Diversification, and Marginalization, 1981–2021
Authors: Coakley Jay
Published: June 2021

This article tells the story of the sociology of sport over the last 4 decades. In the process, it identifies key developments and trends in the field, the questions and topics that have shaped research and the production of knowledge about sports as social phenomena, the challenges currently facing the sociology of sport, and what may happen to the field over the next 40 years.
The American lobster genome reveals insights on longevity, neural, and immune adaptations
Authors: Polinski Jennifer M. , Zimin Aleksey V. , Clark K. Fraser , Kohn Andrea B. , Sadowski Norah , Timp Winston , Ptitsyn Andrey , Khanna Prarthana , Romanova Daria Y. , Williams Peter , Greenwood Spencer J. , Moroz Leonid L. , Walt David R. , Bodnar Andrea G.
Published: June 2021

Innovations in the American lobster genome provide insight into the ecological success of this iconic marine crustacean.
Reappearance of first Shapiro step in narrow topological Josephson junctions
Authors: Rosenbach Daniel , Schmitt Tobias W. , Schüffelgen Peter , Stehno Martin P. , Li Chuan , Schleenvoigt Michael , Jalil Abdur R. , Mussler Gregor , Neumann Elmar , Trellenkamp Stefan , Golubov Alexander A. , Brinkman Alexander , Grützmacher Detlev , Schäpers Thomas
Published: June 2021

Confinement in topological insulator nanoribbon Josephson junctions leads to a gapped electron-hole bound state spectrum.
Harnessing the power of antibodies to fight bone metastasis
Authors: Tian Zeru , Wu Ling , Yu Chenfei , Chen Yuda , Xu Zhan , Bado Igor , Loredo Axel , Wang Lushun , Wang Hai , Wu Kuan-Lin , Zhang Weijie , Zhang Xiang H.-F. , Xiao Han
Published: June 2021

Precision modification of antibodies with bone-targeting moieties unleashes their potential for the treatment of bone metastases.
RUNX1-mediated alphaherpesvirus-host trans-species chromatin interaction promotes viral transcription
Authors: Xiao Ke , Xiong Dan , Chen Gong , Yu Jinsong , Li Yue , Chen Kening , Zhang Lu , Xu Yangyang , Xu Qian , Huang Xi , Gao Anran , Cao Kai , Yan Keji , Dai Jinxia , Hu Xueying , Ruan Yijun , Fu Zhenfang , Li Guoliang , Cao Gang
Published: June 2021

Pseudorabies virus interacts with active regions in host genome to efficiently transcribe viral genes.
Mitigation strategies for airborne disease transmission in orchestras using computational fluid dynamics
Authors: Hedworth Hayden A. , Karam Mokbel , McConnell Josh , Sutherland James C. , Saad Tony
Published: June 2021

Beyond the six-foot rule: Airflow modification is critical in reducing viral transmission risk among musicians.
Dynamic piezoelectric MEMS-based optical metasurfaces
Authors: Meng Chao , Thrane Paul C. V. , Ding Fei , Gjessing Jo , Thomaschewski Martin , Wu Cuo , Dirdal Christopher , Bozhevolnyi Sergey I.
Published: June 2021

Combining piezoelectric MEMS with optical gap-plasmon metasurfaces enables electrically driven dynamic 2D wavefront shaping.
Effects of COVID-19 lockdowns on fine particulate matter concentrations
Authors: Hammer Melanie S. , van Donkelaar Aaron , Martin Randall V. , McDuffie Erin E. , Lyapustin Alexei , Sayer Andrew M. , Hsu N. Christina , Levy Robert C. , Garay Michael J. , Kalashnikova Olga V. , Kahn Ralph A.
Published: June 2021

Satellite-derived PM
2.5
concentrations are produced and examined to assess the effects of COVID-19 lockdowns on PM
2.5
.
A self-amplifying loop of YAP and SHH drives formation and expansion of heterotopic ossification
Authors: Cong Qian , Liu Yuchen , Zhou Taifeng , Zhou Yaxing , Xu Ruoshi , Cheng Caiqi , Chung Hye Soo , Yan Meijun , Zhou Hang , Liao Zhiheng , Gao Bo , Bocobo Geoffrey A. , Covington Taylor A. , Song Hyeon Ju , Su Peiqiang , Yu Paul B. , Yang Yingzi
Published: June 2021

A self-amplifying and propagating loop of YAP-SHH is a core molecular mechanism underlying diverse forms of heterotopic ossification.
Identification of Reductive Dehalogenases That Mediate Complete Debromination of Penta- and Tetrabrominated Diphenyl Ethers in
Dehalococcoides
spp.
Authors: Zhao Siyan , Rogers Matthew J. , Cao Lifeng , Ding Chang , He Jianzhong
Published: June 2021

The ubiquity, toxicity, and persistence of polybrominated diphenyl ethers (PBDEs) in the environment have drawn significant public and scientific interest to the need for the remediation of PBDE-contaminated ecosystems. However, the low bioavailability of PBDEs in environmental compartments typically limits bioremediation of PBDEs and has long impeded the study of anaerobic microbial PBDE removal.
Pathogenic Escherichia coli-Specific Bacteriophages and Polyvalent Bacteriophages in Piglet Guts with Increasing Coliphage Numbers after Weaning
Authors: Lin Yan , Zhou Bei , Zhu Weiyun
Published: June 2021

Previous studies based on metagenomic sequencing reported that gut bacteriophages profoundly influence gut physiology but did not provide information regarding the host range and biological significance. Here, we screened coliphages from preweaned and postweaned piglet gut against indicator hosts, which allowed us to identify the pathogenic
E. coli
-specific bacteriophages and polyvalent bacteriophages in pig farms and quantify their presence.
Structure, Immunogenicity, and Conformation-Dependent Receptor Binding of the Postfusion Human Metapneumovirus F Protein
Authors: Huang Jiachen , Chopra Pradeep , Liu Lin , Nagy Tamas , Murray Jackelyn , Tripp Ralph A. , Boons Geert-Jan , Mousa Jarrod J.
Published: June 2021

Human metapneumovirus (hMPV) is an important cause of viral respiratory disease. In this paper, we report the X-ray crystal structure of the hMPV fusion (F) protein in the postfusion conformation from genotype B.
Both Pseudomonas aeruginosa and Candida albicans Accumulate Greater Biomass in Dual-Species Biofilms under Flow
Authors: Kasetty Swetha , Mould Dallas L. , Hogan Deborah A. , Nadell Carey D.
Published: June 2021

There is an abundance of work on both
P. aeruginosa
and
C. albicans
in isolation, and quite some work as well on the way these two microbes interact. These studies do not, however, consider biofilm environments under flow, and our results here show that the expected outcome of interaction between these two pathogens can actually be reversed under flow, from pure antagonism to an increase in biomass on the part of both.
Intravital Imaging of Candida albicans Identifies Differential
In Vitro
and
In Vivo
Filamentation Phenotypes for Transcription Factor Deletion Mutants
Authors: Wakade Rohan S. , Huang Manning , Mitchell Aaron P. , Wellington Melanie , Krysan Damian J.
Published: June 2021

Candida albicans
is one of the most common causes of fungal infections in humans.
C. albicans
undergoes a transition from a round yeast form to a filamentous form during infection, which is critical for its ability to cause disease. Although this transition has been studied in the laboratory for years, methods to do so in an animal model of infection have been limited.
The Burkholderia pseudomallei
hmqA-G
Locus Mediates Competitive Fitness against Environmental Gram-Positive Bacteria
Authors: Mou Sherry , Jenkins Conor C. , Okaro Udoka , Dhummakupt Elizabeth S. , Mach Phillip M. , DeShazer David
Published: June 2021

Burkholderia pseudomallei
naturally resides in water, soil, and the rhizosphere and its success as an opportunistic pathogen is dependent on the ability to persist in these harsh habitats long enough to come into contact with a susceptible host. In addition to adapting to limiting nutrients and diverse chemical and physical challenges,
B. pseudomallei
also has to interact with a variety of microbial competitors.
Supplemental Material: Multi-stage India-Asia collision: Paleomagnetic constraints from Hazara-Kashmir syntaxis in the western Himalaya
Authors: Jadoon Umar Farooq , Huang Baochun
Published: June 2021

Tables S1–S6; Figures S1–S2.
Taxonomic Status of Four Rare Alien Fish Species of the Kapchagay Reservoir (Balkhash Basin, Central Asia)
Authors: Mamilov N. Sh. , Konysbaev T. G. , Magda I. N. , Vasil’eva E. D.
Published: June 2021

Abstract—

Based on the morphological features, four rare alien species in the Kapchagai reservoir were identified: Coregonus peled, Parasalmo mykiss, Megalobrama mantschuricus, and Oreochromis niloticus. The latter two species were recorded for the ichthyofauna of Kazakhstan for the first time. Self-reproducing P. mykiss populations have been known in the Balkhash Basin since the late 1990s, whereas the introduction of C. peled into the Ili basin in 1968−1969 and 1971 did not lead to the naturalization of the species. The reasons for the great diversity of invasive fish species in the Kapchagai reservoir are overviewed.
Role of Semenov’s Theory of Chain Reactions in the Formation of Modern Concepts on the Processes of Combustion, Explosion, and Detonation of Gases
Authors: Azatyan V. V.
Published: June 2021

This paper presents the results of the theoretical and experimental studies of ignition, flame propagation, explosion, and detonation of gases, showing that, contrary to previous concepts, chain mechanisms in combustion reactions play a decisive role not only at pressures tens of times lower than atmospheric pressure in the absence of self-heating but also at higher pressures and any temperature conditions. Examples of the chemical control of all these processes are given. At the same time, the results show the outstanding role of N.N. Semenov’s theory of chain reactions in the development of the theory of the rates of chemical reactions and combustion processes.
Double check: diagnosis and management of adult Hirschsprung disease
Authors: Moynagh Niamh , Rogers Ailin C , Muldoon Cian , McCormick Paul H
Published: June 2021

Hirschsprung disease (HD) is a gut motility disorder usually diagnosed acutely in infancy, although variants of HD may present later in life with indolent symptoms. This report highlights the rarity of diagnosing HD and hypoganglionosis in adulthood and the nuances that need consideration for their surgical management. We present a report of a 49-year-old man presenting with chronic constipation. A full thickness rectal biopsy confirmed aganglionosis, and HD in adulthood was diagnosed. He underwent a defunctioning left-sided colostomy to ensure histological confirmation of ganglia in his left colon, and adequate colonic function via the colostomy.This served also as an assessment of the proximal conduit for any future anastomosis. He later underwent ultra-low anterior resection, coloanal anastomosis and loop ileostomy with subsequent reversal. His final histology revealed hypoganglionosis of the resected segment, with normal innervation to the site of the colostomy. He made full recovery with normal bowel movements.
Positional changes leading to transient ischaemia in a patient with neuroendocrine carcinoma of the lung
Authors: Livesay James , Tahir Hassan , Baljepally Raj
Published: June 2021

Coronary spasm in carcinoid heart disease has an incidence of 10%, but is rare in patients with neuroendocrine tumours without carcinoid heart disease. We present a rare case of right coronary artery spasm and ST elevations secondary to a neuroendocrine carcinoma of the lung, uniquely provoked by positional changes. Our patient is a 55-year-old man with recurrent ST-elevation myocardial infarction secondary to coronary vasospasm that was diagnosed with neuroendocrine carcinoma of the lung. We believe his positional coronary spasm episodes were likely due to intermittent tumour compression from changes in body position. Our case highlights positional coronary spasm as a previously unreported and potentially early manifestation of neuroendocrine carcinoma of the lung.
Pneumocystis jiroveciipneumonia in newly diagnosed treatment-naïve chronic lymphocytic leukaemia
Authors: Springsted Elspeth , Giri Badri , Kollipara Venkateswara
Published: June 2021

A 78-year-old man with newly diagnosed treatment-naïve chronic lymphocytic leukaemia (CLL) was referred to a pulmonary clinic for 1 month of dry cough and dyspnoea on exertion. Further workup with CT of the chest showed patchy ground-glass opacities predominantly on the right side. The patient was started on empiric antibiotic for presumed community-acquired pneumonia but did not have any improvement in his symptoms and eventually required supplemental oxygen. Bronchoscopy with bronchoalveolar lavage from the right middle lobe showedPneumocystis jiroveciicysts on Grocott methenamine silver stains. The patient was HIV negative. He was placed onP. jiroveciipneumonia (PJP) treatment with clindamycin and primaquine due to history of significant allergy to sulfa drugs. The patient’s symptoms completely resolved after a 21-day course of treatment and no longer needed supplemental oxygen. This case highlights the importance of keeping PJP infection in differential diagnosis in both treated and untreated patients with CLL with dyspnoea and pulmonary infiltrates.
Critical care management of hydrofluoric acid burns with a negative outcome
Authors: Prasad Aalekh , Ibrahim Heba , Mortimore Katherine , Vandabona Rohan
Published: June 2021

Hydrofluoric acid is a highly corrosive acid widely used in various industries. When in contact with skin it causes local and systemic reactions due to the generation of fluoride ions. Severe burns are associated with high mortality rates, approaching 100%. We present a 21-year-old man with 15% full thickness burns, severe metabolic acidosis, hypoxia and electrolyte disturbances. The burns were treated with topical and subcutaneous injections of calcium gluconate, and the patient was given intravenous fluid, calcium chloride, magnesium and insulin-glucose infusions. Continuous renal replacement therapy was initiated due to the severity of the systemic toxicity. Extracorporeal membrane oxygenation was considered as it plays a vital role when conventional therapies fail. Our patient suffered multiple cardiac arrests and cardiopulmonary resuscitation was conducted several times but despite extensive efforts, he did not survive.
Recurrent hypoglycaemia and dilated cardiomyopathy: delayed presentation of Sheehan’s syndrome
Authors: Makharia Archita , Lakhotia Manoj , Tiwari Vineet , Gopal Kishan
Published: June 2021

Sheehan’s syndrome (SS) is ischaemic necrosis of the pituitary gland due to massive postpartum haemorrhage. The clinical manifestations may vary from subtle to life-threatening and may present immediately after delivery or many years later. We present a case history of a 58-year-old non-diabetic woman who had undetected SS and presented with two unusual manifestations, including recurrent hypoglycaemia and dilated cardiomyopathy 34 years after delivery. The dilated cardiomyopathy reversed partially after treatment.
‘I haven’t heard much about other methods’: quality of care and person-centredness in a programme to promote the postpartum intrauterine device in Tanzania
Authors: Senderowicz Leigh , Pearson Erin , Hackett Kristy , Huber-Krum Sarah , Francis Joel Msafiri , Ulenga Nzovu , Bärnighausen Till
Published: June 2021

Background

Programmes promoting the postpartum intrauterine device (PPIUD) have proliferated throughout South Asia and sub-Saharan Africa in recent years, with proponents touting this long-acting reversible contraceptive (LARC) method’s high efficacy and potential to meet contraceptive unmet need. While critiques of LARC-first programming abound in the Global North, there have been few studies of the impact of LARC-centric programmes on patient-centred outcomes in the Global South.

Methods

Here, we explore the impact of a PPIUD intervention at five Tanzanian hospitals and their surrounding satellite clinics on quality of contraceptive counselling and person-centred care using 20 qualitative in-depth interviews with pregnant women seeking antenatal care at one of those clinics. Using a modified version of the contraceptive counselling quality framework elaborated by Holt and colleagues, we blend deductive analysis with an inductive approach based on open coding and thematic analysis.

Results

Interpersonal aspects of relationship building during counselling were strong, but a mix of PPIUD intervention-related factors and structural issues rendered most other aspects of counselling quality low. The intervention led providers to emphasise the advantages of the IUD through biased counselling, and to de-emphasise the suitability of other contraceptive methods. Respondents reported being counselled only about the IUD and no other methods, while other respondents reported that other methods were mentioned but disparaged by providers in relation to the IUD. A lack of trained providers meant that most counselling took place in large groups, resulting in providers’ inability to conduct needs assessments or tailor information to women’s individual situations.

Discussion

As implemented, LARC-centric programmes like this PPIUD intervention may decrease access to person-centred contraceptive counselling and to accurate information about a broad range of contraceptive methods. A shift away from emphasising LARC methods to more comprehensive, person-centred contraceptive counselling is critical to promote contraceptive autonomy.
Tailored mHealth intervention for improving treatment adherence for people living with HIV in Iran (HamRaah): protocol for a feasibility study and randomised pilot trial with a nested realist evaluation
Authors: Ameli Vira , Haberer Jessica , Sabin Lora , Meinck Franziska , Barlow Jane , Taj Leila , Mohraz Minoo
Published: June 2021

Introduction

Middle East and North Africa (MENA) has a rising rate of new HIV infections and AIDS-related mortality. Consistent adherence to antiretroviral therapy (ART) leads to viral suppression, preventing HIV transmission and treatment failure. mHealth interventions can improve ART adherence by providing tailored support and directing patients to existing healthcare services. HamRaah (Persian for ‘together-in-path’) is the first mHealth-based intervention in a MENA country and is designed to improve adherence through two-way mobile messaging for people recently diagnosed with HIV in Tehran, Iran. The objectives of this pilot randomised controlled trial (RCT) are to examine the feasibility, acceptability and preliminary effectiveness of HamRaah, and to develop an explanatory theory for any observed effects through a nested realist evaluation.

Methods

A feasibility study and two-arm RCT of HamRaah, with an embedded realist evaluation will be conducted. Participants will be randomised 1:1 to HamRaah or routine care for a 6-month intervention. The initial effectiveness of HamRaah will be assessed through the primary outcome of self-reported ART adherence and several secondary outcomes: retention in care, CD4 count and viral suppression. A theory-driven realist evaluation framework will be used to develop an explanatory theory regarding what works, for whom, how and in what context.

Ethics and dissemination

The study received ethical clearance from Tehran University of Medical Sciences Ethics Committee and Oxford Tropical Research Ethics Committee People living with HIV in Tehran and key country stakeholders in HIV policy and programming have been involved in the development of HamRaah and this pilot trial. Participants will provide informed consent prior to study enrolment. The results will be disseminated to all stakeholders and presented in peer-reviewed journal publications and conferences.

Trial registration number

IRCT20100601004076N23; Pre-results.
Recompensation factors for patients with decompensated cirrhosis: a multicentre retrospective case–control study
Authors: Xu Xiaomei , Wang Haolin , Zhao Wenlong , Wang Yong , Wang Jiayue , Qin Bo
Published: June 2021

Objectives

We aimed to evaluate recompensation factors among patients with decompensated cirrhosis.

Design

A multicentre retrospective case–control study was conducted. Data were collected from and compared between groups of patients with recompensated and acute decompensated cirrhosis. Univariable and multivariable logistic regressions were used to select indicators associated with recompensation among patients with decompensated cirrhosis with different complications. A decision tree with 10-fold cross-validation was used to develop the model to identify patients with recompensation. We followed the transparent reporting of a multivariable prediction model for individual prognosis or diagnosis (TRIPOD) guideline for development and reporting of the new model.

Setting

The study was conducted in six tertiary public hospitals in Chongqing, China.

Participants

This study included 3953 patients with decompensated cirrhosis.

Results

In the total sample of included patients, there were 553 patients with recompensation and 3400 patients with acute decompensation, including 1158 patients with gastrointestinal bleeding, 1715 patients with a bacterial infection, 104 patients with hepatic encephalopathy and 423 patients with ascites. The most relevant indicator of recompensation selected by the decision tree model was albumin, with a threshold of 40 g/L. Total protein, haemoglobin, basophil percentage, alanine aminotransferase, neutrophil-to-lymphocyte ratio and diabetes were also selected to subsequently distinguish patients. The terminal nodes with a probability of recompensation was 0.89. The overall accuracy rate of the model was 0.92 (0.91–0.93), and it exhibited high specificity (86.9%) and sensitivity (92.6%).

Conclusions

The occurrence of recompensated cirrhosis could be identified by albumin, total protein, haemoglobin, basophil percentage, alanine aminotransferase, neutrophil-to-lymphocyte ratio and diabetes. These simple variables may help clinicians develop a treatment plan to encourage patients with decompensated cirrhosis to recompensate.
Parents, healthcare professionals and other stakeholders’ experiences of caring for babies born too soon in a low-resource setting: a qualitative study of essential newborn care for preterm infants in Kenya
Authors: Mitchell Eleanor J , Pallotti Phoebe , Qureshi Zahida P , Daniels Jane P , Oliver Mary , Were Fredrick , Osoti Alfred , Gwako George , Kimani Violet , Opira Jacqueline , Ojha Shalini
Published: June 2021

Objectives

Prematurity is the leading cause of global neonatal and infant mortality. Many babies could survive by the provision of essential newborn care. This qualitative study was conducted in order to understand, from a family and professional perspective, the barriers and facilitators to essential newborn care. The study will inform the development of an early warning score for preterm and low birthweight infants in low and middle income countries (LMICs).

Setting

Single-centre, tertiary referral hospital in Nairobi, Kenya.

Participants

Nineteen mothers and family members participated in focus group discussions and 20 key-informant interviews with professionals (healthcare professionals and policy-makers) were conducted. Focus group participants were identified via postnatal wards, the newborn unit and Kangaroo Mother Care (KMC) unit. Convenience and purposive sampling was used to identify professionals.

Outcome measures

Understanding facilitators and barriers to provision of essential newborn care in preterm infants.

Results

From 27 themes, three global themes emerged from the data: mothers’ physical and psychological needs, system pillars and KMC.

Conclusion

Meeting mothers’ needs in the care of their babies is important to mothers, family members and professionals, and deserves greater attention. Functioning system pillars depended on a standardised approach to care and low cost, universally applicable interventions are needed to support the existing care structure. KMC was effective in both meeting mothers’ needs, supporting existing care structures and also provided a space for the resolution of the dialectical relationship between families and hospital procedures. Lessons learnt from the implementation of KMC could be applied to the development of an early warning score in LMICs.
Protocol for a randomised controlled trial comparing two CPAP levels to prevent extubation failure in extremely preterm infants
Authors: Kidman Anna Madeline , Manley Brett James , Boland Rosemarie Anne , Malhotra Atul , Donath Susan M , Davis Peter G , Bhatia Risha
Published: June 2021

Introduction

Respiratory distress syndrome is a complication of prematurity and extremely preterm infants born before 28 weeks’ gestation often require endotracheal intubation and mechanical ventilation. In this high-risk population, mechanical ventilation is associated with lung injury and contributes to bronchopulmonary dysplasia. Therefore, clinicians attempt to extubate infants as quickly and use non-invasive respiratory support such as nasal continuous positive airway pressure (CPAP) to facilitate the transition. However, approximately 60% of extremely preterm infants experience ‘extubation failure’ and require reintubation. While CPAP pressures of 5–8 cm H2O are commonly used, the optimal CPAP pressure is unknown, and higher pressures may be beneficial in avoiding extubation failure. Our trial is the Extubation CPAP Level Assessment Trial (ÉCLAT). The aim of this trial is to compare higher CPAP pressures 9–11 cm H2O with a current standard pressures of 6–8 cmH2O on extubation failure in extremely preterm infants.

Methods and analysis

200 extremely preterm infants will be recruited prior to their first extubation from mechanical ventilation to CPAP. This is a parallel group randomised controlled trial. Infants will be randomised to one of two set CPAP pressures: CPAP 10 cmH2O (intervention) or CPAP 7 cmH2O (control). The primary outcome will be extubation failure (reintubation) within 7 days. Statistical analysis will follow standard methods for randomised trials on an intention to treat basis. For the primary outcome, this will be by intention to treat, adjusted for the prerandomisation strata (GA and centre). We will use the appropriate parametric and non-parametric statistical tests.

Ethics and dissemination

Ethics approval has been granted by the Monash Health Human Research Ethics Committees. Amendments to the trial protocol will be submitted for approval. The findings of this study will be written into a clinical trial report manuscript and disseminated via peer-reviewed journals (on-line or in press) and presented at national and international conferences.

Trial registration number

ACTRN12618001638224; pre-results.
Birth control pills and risk of hypothyroidism: a cross-sectional study of the National Health and Nutrition Examination Survey, 2007–2012
Authors: Qiu Yuxuan , Hu Yuanyuan , Xing Zhichao , Fu Qingyu , Zhu Jingqiang , Su Anping
Published: June 2021

Objective

The association between use of birth control pills and thyroid function in women has not ever been well studied, but potential risk has been implicated by small sample-sized studies. We aimed to determine this association using a large epidemiological survey.

Design

Cross-sectional study.

Setting

National Health and Nutrition Examination Survey conducted in the USA from 2007 to 2012.

Participants

Female respondents aged 18+ who had data on history of taking birth control pills and thyroid function were included. History of taking birth control pills was based on responses on the reproductive health questionnaire. Participants not on antithyroid medication with thyroid-stimulating hormone (TSH) >5.6 mIU/L and those on thyroid hormone replacement regardless of TSH were categorised as hypothyroid. Participants not on thyroid hormone replacement or antithyroid medication who had TSH between 0.34 mIU/L and 5.6 mIU/L were classified as euthyroid.

Primary and secondary outcome measures

Association between use of birth control pills and hypothyroidism based on multivariate logistic regression analysis.

Results

A total of 5116 female adults with history of taking birth control pills (n=3034) and without (n=2082) were included. A higher prevalence of hypothyroidism was found in those who have ever taken birth control pills (17.7% vs 14.1%; p=0.003). Multivariate logistic regression adjusted for confounding covariables, including age, race, education, body mass index, smoking status, alcohol use, history of thyroid disease, current thyroid disease, first menstrual age, pregnancy history, menopause status and history of hormone replacement use, demonstrated a significant association between history of taking birth control pills for more than 10 years and hypothyroidism (OR, 3.837; 95% CI 1.402 to 10.500; p=0.009).

Conclusions

Longer history of using birth control pills was strongly associated with hypothyroidism, especially for more than 10 years.
Association between comorbid sleep apnoea–hypopnoea syndrome and prognosis of intensive care patients: a retrospective cohort study
Authors: Wang Hongxia , Shao Guangqiang , Rong Lei , Ji Yang , Zhang Keke , Liu Min , Ma Ling
Published: June 2021

Objective

In this study, we investigated the association between comorbid sleep apnoea–hypopnoea syndrome (SAHS) and the prognosis of patients in an intensive care unit (ICU) to determine whether this relationship varies between different disease subgroups.

Methods

We conducted a retrospective cohort study using publicly available information from the critical care database Medical Information Mart for Intensive Care III. Adults (≥18 years of age) who attended the ICU for the first time were enrolled. Demographic information and clinical data were obtained from each patient. The primary outcome was 30-day mortality after ICU admission, and the secondary outcomes were in-hospital and ICU mortality. Multivariate logistic regression and Cox regression analyses were used to examine the associations between SAHS comorbidities and the research outcomes. Propensity score matching was used to adjust for potential confounding variables.

Results

Of the 32 989 patients enrolled, 1918 (5.81%) were diagnosed with SAHS as a comorbid condition. Patients with SAHS had a significantly lower 30-day mortality rate compared with those without SAHS (5.27% vs 13.65%, respectively; p<0.001). The frequency of chronic obstructive pulmonary disease, cerebral disease, cardiovascular disease, hypertension, diabetes mellitus and renal failure was significantly different between the two groups. Patients with SAHS demonstrated significantly longer survival compared with patients without SAHS. Multivariate Cox proportional hazards regression identified a significant relationship between SAHS and mortality within 30 days (adjusted HR=0.610, 95% CI 0.499 to 0.747, p<0.0001).

Conclusion

SAHS as a comorbid condition decreases the risk of 30-day mortality, in-hospital mortality and ICU mortality among ICU patients.
What is the impact of multimorbidity on the risk of hospitalisation in older adults? A systematic review study protocol
Authors: Rodrigues Luciana Pereira , Rezende Andréa Toledo de Oliveira , Moura Letícia de Almeida Nogueira e , Nunes Bruno Pereira , Noll Matias , de Oliveira Cesar , Silveira Erika Aparecida
Published: June 2021

Introduction

The development of multiple coexisting chronic diseases (multimorbidity) is increasing globally, along with the percentage of older adults affected by it. Multimorbidity is associated with the concomitant use of multiple medications, a greater possibility of adverse effects, and increased risk of hospitalisation. Therefore, this systematic review study protocol aims to analyse the impact of multimorbidity on the occurrence of hospitalisation in older adults and assess whether this impact changes according to factors such as sex, age, institutionalisation and socioeconomic status. This study will also review the average length of hospital stay and the occurrence of hospital readmission.

Methods and analysis

A systematic review of the literature will be carried out using the PubMed, Embase and Scopus databases. The inclusion criteria will incorporate cross-sectional, cohort and case–control studies that analysed the association between multimorbidity (defined as the presence of ≥2 and/or ≥3 chronic conditions and complex multimorbidity) and hospitalisation (yes/no, days of hospitalisation and number of readmissions) in older adults (aged ≥60 years or >65 years). Effect measures will be quantified, including ORs, prevalence ratios, HRs and relative risk, along with their associated 95% CI. The overall aim of this study is to widen knowledge and to raise reflections about the association between multimorbidity and hospitalisation in older adults. Ultimately, its findings may contribute to improvements in public health policies resulting in cost reductions across healthcare systems.

Ethics and dissemination

Ethical approval is not required. The results will be disseminated via submission for publication to a peer-reviewed journal when complete.

PROSPERO registration number

CRD42021229328.
Preliminary case report study of training and support needed to conduct bowtie analysis in healthcare
Authors: McLeod Ronald , Russell Wendy , Stewart Marjorie , Prentice Mark , Bowie Paul
Published: June 2021

Background

There is limited engagement in healthcare with the kinds of proactive approaches to risk assessment used in other industries. Bowtie analysis (BTA) has previously been shown to have potential as a straightforward approach to proactively assessing risk in healthcare. The visual nature of BTA diagrams can aid communication of the essential elements of a complex risk management system. The aim of this small case report study was to investigate the training and support likely to be needed for existing healthcare professionals to conduct BTA in compliance with recognised industry best-practice.

Method

Of 17 volunteers who attended training, 3 completed an analysis of significant healthcare risks in the study period: misadministration of gentamicin; unknown development of acute kidney injury and disposal of medical devices containing patient identifiable information (PII). Subjective assessments of the quality of the analyses were made against indicators of BTA best-practice.

Results

Use of the BTA method led to a deeper understanding of the issues and a more thorough understanding of the risks and what was needed to control them than would have been the case if ‘normal practice’ had been followed. Classroom-based training supported by written guidance; however, do not appear adequate to support development of competence to carry out a quality BTA in a healthcare setting.

Conclusions

BTA seems to have potential though further evaluation of its application and utility is necessary. The most cost-effective and productive approach is likely to be to train a small number of people to develop deeper skills and experience in BTA. In addition to training and user guidance, the opportunity to facilitate at least one analysis, with some specialist/trainer support, appears to be essential in developing BTA competence.
Author response to Colleet al
Authors: Fucà Giovanni , Corti Francesca , Pietrantonio Filippo
Published: June 2021

The event of pseudoprogression is rare in patients with MSI-high metastatic colorectal cancer receiving immune checkpoint inhibitors. In this response to the Letter to the Editor by Colleet al, we highlight that the timing of disease re-assessment may influence the incidence of pseudoprogression, with early assessments being associated with higher incidence. Such dynamics should be considered when interpreting the efficacy of treatment.
Predictors of spontaneous resolution of umbilical hernia in children
Authors: Kaur Manvinder , Grandpierre Viviane , Oltean Irina , Weir Arielle , Nasr Ahmed
Published: June 2021

Objective

The aims were to describe the management of umbilical hernias, to define postoperative complications, and to identify the characteristics of patients that were more likely to have spontaneous resolution of their hernia.

Methods

All patients referred for umbilical hernia at the Children’s Hospital of Eastern Ontario from January 1990 to April 2017 were examined via retrospective chart review. Spontaneous resolution of umbilical hernia was examined using binary logistic regression.

Results

We included 2621 patients presenting with an umbilical hernia. A total of 1587 (60.5%) patients underwent surgical repair at a median age of 3.6 years (IQR 2.3–5.4). Surgical complications consisted of infection (n=3), bleeding (n=3), hematoma (n=3), and anesthesia-related complications (n=3). For every one-unit increase in defect size, the odds of a spontaneous resolution of the hernia were 5% lower while controlling for prematurity and the presence of comorbidities [adjusted odds ratio (aOR)=0.95; 95% confidence intervel (CI) 0.93 to 0.97]. Premature babies were 80% less likely to experience hernia resolution compared with non-premature babies (aOR=0.20; 95% CI 0.03 to 0.74).

Conclusion

The odds of spontaneous resolution were lower for premature babies and were negatively correlated with defect size.
Weak decays of bottom-charm baryons: $$\mathcal {B}_{bc}\rightarrow \mathcal {B}_bP$$
Authors: Han Jia-Jie , Zhang Rui-Xiang , Jiang Hua-Yu , Xiao Zhen-Jun , Yu Fu-Sheng
Published: June 2021

After the discovery of the double-charm baryon $$\Xi _{cc}^{++}$$

Ξ

cc

+
+

by LHCb, one of the most important topics is to search for the bottom-charm baryons which contain a b quark, a c quark and a light quark. In this work, we study the two-body non-leptonic weak decays of a bottom-charm baryon into a spin-1/2 bottomed baryon and a light pseudoscalar meson with the short-distance contributions calculated under the factorization hypothesis and the long-distance contributions considering the final-state-interaction effects. The branching fractions of all fifty-seven decay channels are estimated. The results indicate that $$\Xi _{bc}^+\rightarrow \Xi _b^0\pi ^+$$

Ξ

bc

+

→

Ξ
b
0

π
+

, $$\Xi _{bc}^{0}\rightarrow \Xi _{b}^{-}\pi ^+$$

Ξ

bc

0

→

Ξ

b

-

π
+

and $$\Omega _{bc}^0\rightarrow \Omega _b^-\pi ^+$$

Ω

bc

0

→

Ω
b
-

π
+

decay modes have relatively large decay rates and thus could be used to experimentally search for the bottom-charm baryons. The topological diagrams and the SU(3) symmetry of bottom-charm baryon decays are discussed.
Metric connections with parallel twistor-free torsion
Authors: Moroianu Andrei , Pilca Mihaela
Published: June 2021

The torsion of every metric connection on a Riemannian manifold has three components: one totally skew-symmetric, one of vectorial type and one of twistorial type, which is also called the traceless cyclic component. In this paper we classify complete simply connected Riemannian manifolds carrying a metric connection whose torsion is parallel, has nonzero vectorial component and vanishing twistorial component.
The impact of deformed space—space parameters into canonical scalar field model with exponential potential. The case of spatially flat Friedmann—Lemaître—Robertson—Walker (FLRW) universe
Authors: Toghrai T. , Mansour N. , Daoudia A. K. , El Boukili A. , Sedra M. B.
Published: June 2021

In this work, we propose a model of noncommutative cosmology through the deformation of minisuperspace. We focus on an exponentially potential with a homogeneous scalar field minimally coupled to gravity in the spatially flat universe. To process, we use a particular case of noncommutativity by making a deformation of space coordinates only. Then, we compare results in both the commutative model and the noncommutative one.