bluuebunny/crossref_metadata_2025 huggingface dataset:
Cryptogenic organising pneumonia: an unusual cause of pleuritic chest pain
Authors: Ceci Bonello Rebecca , Ceci Bonello Etienne , Vassallo Christian , Bellia Edward Giles
Published: January 2021

A 76-year-old woman presented with a 2-hour history of pleuritic chest pain with no other associated symptoms. Blood investigations revealed raised inflammatory markers and an elevated white cell count. On chest radiograph, an airspace shadow indicative of a consolidation was prominent. This was followed by a CT scan of her thorax which showed a spiculated lesion in the right upper lobe, a lesion in the posterior segment of the left lower lobe and mildly enlarged right hilar lymph nodes. She was started on dual antibiotic therapy; however, the patient’s clinical status and inflammatory markers did not improve. A bronchoscopy was performed which excluded malignancy and atypical pathogens. CT-guided biopsy confirmed the presence of cryptogenic organising pneumonia. Prednisolone 50 mg daily was prescribed with quick resolution of symptoms.
Severe phytophotodermatitis from fig sap: a little known phenomenon
Authors: Redgrave Natalie , Solomon Joshua
Published: January 2021

A 46-year-old arborist with no medical history presented to the emergency department with a confluent blistering, erythematous, non-pruritic, painful rash covering both arms circumferentially and the back of his neck. He sought medical advice as his arms were becoming more painful and swollen with blister formation, despite aloe vera cream and wet towel wraps. He recalled that 2 days previously he had been pruning a fig tree on a hot sunny day. He was wearing a t-shirt and his forearms had been exposed to a large quantity of fig sap, while he was working under direct sunlight. On examination, there were several blisters with no superimposed infection. He was diagnosed with phytophotodermatitis and referred to a regional burns unit. He recovered well with simple dressings and a course of antibiotics. At present, he has made a good recovery with no long-term sequelae such as skin hyperpigmentation or hypopigmentation.
Development of a large spontaneous pneumothorax after recovery from mild COVID-19 infection
Authors: Nunna Krishidhar , Braun Andrea Barbara
Published: January 2021

A previously healthy 37-year-old man presented with fevers and myalgias for a week with a minimal dry cough. Initial SARS-CoV-2 nasopharyngeal testing was negative, but in light of high community prevalence, he was diagnosed with COVID-19, treated with supportive care and self-quarantined at home. Three days after resolution of all symptoms, he developed sudden onset chest pain. Chest imaging revealed a large right-sided pneumothorax and patchy subpleural ground glass opacities. IgM and IgG antibodies for SARS-CoV-2 were positive. His pneumothorax resolved after placement of a small-bore chest tube, which was removed after 2 days.

This case demonstrates that patients with COVID-19 can develop a significant pulmonary complication, a large pneumothorax, despite only minimal lower respiratory tract symptoms and after resolution of the original illness. Medical professionals should consider development of a pneumothorax in patients who have recovered from COVID-19 and present with new respiratory symptoms.
Severe hypercalcaemia secondary to relapsed Graves’ disease
Authors: Khan Haris , Nawaz Maimoona , Schofield Jonathan , Soran Handrean
Published: January 2021

A 21-year-old woman presented to hospital with abdominal pain and nausea. She had a history of Graves’ disease which had been effectively treated with carbimazole for 15 months. Investigations revealed a serum adjusted calcium level of 3.69 mmol/L with a suppressed parathyroid hormone, thyroid stimulating hormone <0.01 mu/L (0.2–5.0) and free T4 of 76.1 pmol/L (9-24). She was treated as a relapsed case of Graves’ disease and started on propylthiouracil. Calcium levels continued to increase over the next 3 days despite adequate fluid resuscitation. A decision was taken to administer intravenous bisphosphonate (pamidronate) which resulted in a lowering of calcium levels. She became mildly hypocalcaemic following treatment with pamidronate which was presumed secondary to low vitamin D and oral vitamin D replacement was commenced. This case was unique as this is to our knowledge the most significant hypercalcaemia observed in a patient with hyperthyroidism. All other causes of hypercalcaemia were excluded. The learning points were recognising hypercalcaemia as a complication of thyrotoxicosis and the risk of hypocalcaemia following bisphosphonate therapy with low vitamin D stores.
Spontaneous iliacus haematoma with femoral nerve palsy: an appeal to involve surgical teams early
Authors: Crawford Alexander M , Guild Theodore T , Striano Brendan M , Von Keudell Arvind G
Published: January 2021

We report the case of a 68-year-old man who was placed on heparin as bridge therapy and subsequently developed an iliacus haematoma with associated femoral nerve palsy. His team involved the orthopaedic surgery team in delayed fashion after his symptom onset. Due to his active medical conditions, he did not undergo surgical decompression of his haematoma until late into his hospital course. Unfortunately, this patient did not regain meaningful function from his femoral nerve deficit. We believe this case highlights the high index of suspicion necessary for making this diagnosis as well as the repercussions of an untimely decompression for this acute, compressive neuropathy. Although we are surgeons and this is a surgical case, we hope to publish this case in a medical journal to raise awareness that surgical decompression does have a role in this diagnosis and should ultimately be pursued early in its course for optimal patient benefit.
Patient creates filtering bleb: hypotony following traumatic rupture of an old scleral incision for intracapsular cataract surgery
Authors: Lemmens Sophie , Hua Minh-Tri , Stalmans Ingeborg
Published: January 2021

An 86-year-old woman presented with symptomatic hypotony on the left eye since a few weeks, blurry vision and a very sensitive eye. She had a history of bilateral intracapsular cataract extraction (ICCE) in 1982 and secondary intraocular lens implantation in 1988. The patient mentioned a fall on the left side of the head 6 months earlier. The diagnosis of a superior scleral fistula was made, confirmed by gonioscopy and anterior segment optical coherence tomography. Direct surgical repair of the fistula led to a favourable outcome. This case demonstrates the occurrence of symptomatic hypotony due to the traumatic creation of a scleral fistula with an inadvertent filtering bleb many years after ICCE, and the resolution of signs and symptoms after surgical repair. Conventional as well as contemporary modalities can be valuable in the assessment of such fistulae. Management depends on the clinical course and the mechanism and extent of fistulation.
Management of unilateral idiopathic masseter muscle hypertrophy with botulinum toxin type A
Authors: Nilesh Kumar , Dharamsi Ravina , Patil Pankaj , Mate Payal
Published: January 2021

Masseter hypertrophy (MH) is an uncommon disorder which can cause both aesthetic and functional problems. The most common aetiological factors associated with MH are habit of chewing gum, clenching and/or bruxism. The treatment of MH includes conservative management as well as surgical resection of the enlarged muscle and/or bone. Injection of botulinum toxin type A is a relatively new and minimally invasive method for management of masseter muscle hypertrophy, which offers many advantages over conventional surgical management. This paper reports a case of unilateral MH of unknown origin which was treated with injection of botulinum toxin type A, resulting in satisfactory reduction in the volume of muscle and improvement of facial aesthetics.
Bivalirudin and thrombolytic therapy: a novel successful treatment of severe aortic arch thrombosis in a term neonate
Authors: Taha Amjad , Rajgarhia Ayan , Alsaleem Mahdi
Published: January 2021

An early-term infant with uncomplicated perinatal history was found to have a large thrombus in the aortic arch after he failed regular newborn critical congenital heart defect screen. He responded well to bivalirudin thrombolytic and tissue-plasminogen activator (tPA) combination therapy, with a significant resolution of the thrombus. The infant tolerated hospital admission well with no significant complications. He was discharged home on daily aspirin at 2 weeks of life. To our knowledge, the combination therapy approach with bivalirudin and tPA is the first one reported in the literature in the neonatal age group.
Management of non-alcoholic fatty liver disease
Authors: Petroni Maria Letizia , Brodosi Lucia , Bugianesi Elisabetta , Marchesini Giulio
Published: January 2021

Non-alcoholic fatty liver disease is a very common medical condition, driven by a combination of genetic and lifestyle factors, ultimately producing a severe chronic liver disease and increased cardiovascular risk. Most people are asymptomatic for a long time, and their daily life is unaffected, leading to difficulty in identifying and managing people who slowly progress to non-alcoholic steatohepatitis (NASH), NASH-cirrhosis, and eventually hepatocellular carcinoma. Despite advances in the understanding of pathogenic mechanisms and the identification of liver fibrosis as the strongest factor in predicting disease progression, no specific treatments have been approved by regulatory agencies. Outside controlled trials, treatment is generally limited to lifestyle intervention aimed at weight loss. Pioglitazone remains the drug of choice to reduce progression of fibrosis in people with diabetes, although it is often used off-label in the absence of diabetes. Vitamin E is mainly used in children and may be considered in adults without diabetes. Several drugs are under investigation according to the agreed targets of reduced NASH activity without worsening of fibrosis or improving fibrosis without worsening of NASH. Anti-inflammatory, anti-fibrotic agents and metabolism modulators have been tested in either phase III or phase IIb randomized controlled trials; a few failed, and others have produced marginally positive results, but only a few are being tested in extension studies. The development of non-invasive, easily repeatable surrogate biomarkers and/or imaging tools is crucial to facilitate clinical studies and limit liver biopsy.
Electronic health record alerts for acute kidney injury: multicenter, randomized clinical trial
Authors: Wilson F Perry , Martin Melissa , Yamamoto Yu , Partridge Caitlin , Moreira Erica , Arora Tanima , Biswas Aditya , Feldman Harold , Garg Amit X , Greenberg Jason H , Hinchcliff Monique , Latham Stephen , Li Fan , Lin Haiqun , Mansour Sherry G , Moledina Dennis G , Palevsky Paul M , Parikh Chirag R , Simonov Michael , Testani Jeffrey , Ugwuowo Ugochukwu
Published: January 2021

Objective

To determine whether electronic health record alerts for acute kidney injury would improve patient outcomes of mortality, dialysis, and progression of acute kidney injury.

Design

Double blinded, multicenter, parallel, randomized controlled trial.

Setting

Six hospitals (four teaching and two non-teaching) in the Yale New Haven Health System in Connecticut and Rhode Island, US, ranging from small community hospitals to large tertiary care centers.

Participants

6030 adult inpatients with acute kidney injury, as defined by the Kidney Disease: Improving Global Outcomes (KDIGO) creatinine criteria.

Interventions

An electronic health record based “pop-up” alert for acute kidney injury with an associated acute kidney injury order set upon provider opening of the patient’s medical record.

Main outcome measures

A composite of progression of acute kidney injury, receipt of dialysis, or death within 14 days of randomization. Prespecified secondary outcomes included outcomes at each hospital and frequency of various care practices for acute kidney injury.

Results

6030 patients were randomized over 22 months. The primary outcome occurred in 653 (21.3%) of 3059 patients with an alert and in 622 (20.9%) of 2971 patients receiving usual care (relative risk 1.02, 95% confidence interval 0.93 to 1.13, P=0.67). Analysis by each hospital showed worse outcomes in the two non-teaching hospitals (n=765, 13%), where alerts were associated with a higher risk of the primary outcome (relative risk 1.49, 95% confidence interval 1.12 to 1.98, P=0.006). More deaths occurred at these centers (15.6% in the alert group
v
8.6% in the usual care group, P=0.003). Certain acute kidney injury care practices were increased in the alert group but did not appear to mediate these outcomes.

Conclusions

Alerts did not reduce the risk of our primary outcome among patients in hospital with acute kidney injury. The heterogeneity of effect across clinical centers should lead to a re-evaluation of existing alerting systems for acute kidney injury.

Trial registration

ClinicalTrials.gov
NCT02753751
.
Neurovascular coupling alterations in type 2 diabetes: a 5-year longitudinal MRI study
Authors: Zhang Yang , Zhang Xiaolu , Ma Guangyang , Qin Wen , Yang Jiayang , Lin Jiahui , Zhang Quan
Published: January 2021

Introduction

Respective alterations in resting-state brain neural activity and cerebral blood flow (CBF) in type 2 diabetes mellitus (T2DM) have been reported. However, their coupling alteration in T2DM remains largely unknown.

Research design and methods

Twenty-seven patients with T2DM aged 40–67 years and 36 well-matched healthy controls (HCs) underwent resting-state functional MRI (rs-fMRI) and arterial spin labeling (ASL) scans at two time points with a 5-year interval. Regional homogeneity (ReHo) and CBF were calculated from rs-fMRI and ASL, respectively. The standardized ReHo:CBF ratio (mReHo:mCBF ratio), the spontaneous neuronal activity per unit CBF supply, was compared between the two time points. Relationships between the mReHo:mCBF ratio and memory performance were analyzed.

Results

Over 5 years, decreased mReHo:mCBF ratios in patients with T2DM were mainly distributed in four regions, among which the left insula exhibited more severely decreased mReHo:mCBF ratio in patients with T2DM than in HCs, while the left postcentral gyrus, the right Rolandic operculum, and the right precentral gyrus showed no significant intergroup difference. Correlations between the mReHo:mCBF ratio and memory performance were also found in patients with T2DM.

Conclusions

This study suggests that T2DM may accelerate neurovascular coupling impairment in specific brain regions (the left insula), contributing to memory decline. This study implies that the mReHo:mCBF ratio is a potential imaging marker for detecting neurovascular changes.
Workforce capacity for the care of patients with kidney failure across world countries and regions
Authors: Riaz Parnian , Caskey Fergus , McIsaac Mark , Davids Razeen , Htay Htay , Jha Vivekanand , Jindal Kailash , Jun Min , Khan Maryam , Levin Adera , Lunney Meaghan , Okpechi Ikechi , Pecoits-Filho Roberto , Osman Mohamed A , Vachharajani Tushar , Ye Feng , Harris David , Tonelli Marcello , Johnson David , Bello Aminu
Published: January 2021

Introduction

An effective workforce is essential for optimal care of all forms of chronic diseases. The objective of this study was to assess workforce capacity for kidney failure (KF) care across world countries and regions.

Methods

Data were collected from published online sources and a survey was administered online to key stakeholders. All country-level data were analysed by International Society of Nephrology region and World Bank income classification.

Results

The general healthcare workforce varies by income level: high-income countries have more healthcare workers per 10 000 population (physicians: 30.3; nursing personnel: 79.2; pharmacists: 7.2; surgeons: 3.5) than low-income countries (physicians: 0.9; nursing personnel: 5.0; pharmacists: 0.1; surgeons: 0.03). A total of 160 countries responded to survey questions pertaining to the workforce for the management of patients with KF. The physicians primarily responsible for providing care to patients with KF are nephrologists in 92% of countries. Global nephrologist density is 10.0 per million population (pmp) and nephrology trainee density is 1.4 pmp. High-income countries reported the highest densities of nephrologists and nephrology trainees (23.2 pmp and 3.8 pmp, respectively), whereas low-income countries reported the lowest densities (0.2 pmp and 0.1 pmp, respectively). Low-income countries were most likely to report shortages of all types of healthcare providers, including nephrologists, surgeons, radiologists and nurses.

Conclusions

Results from this global survey demonstrate critical shortages in workforce capacity to care for patients with KF across world countries and regions. National and international policies will be required to build a workforce capacity that can effectively address the growing burden of KF and deliver optimal care.
Towards biomarkers for outcomes after pancreatic ductal adenocarcinoma and ischaemic stroke, with focus on (co)-morbidity and ageing/cellular senescence (SASKit): protocol for a prospective cohort study
Authors: Henze Larissa , Walter Uwe , Murua Escobar Hugo , Junghanss Christian , Jaster Robert , Köhling Rüdiger , Lange Falko , Salehzadeh-Yazdi Ali , Wolkenhauer Olaf , Hamed Mohamed , Barrantes Israel , Palmer Daniel , Möller Steffen , Kowald Axel , Heussen Nicole , Fuellen Georg
Published: January 2021

Introduction

Ageing-related processes such as cellular senescence are believed to underlie the accumulation of diseases in time, causing (co)morbidity, including cancer, thromboembolism and stroke. Interfering with these processes may delay, stop or reverse morbidity. The aim of this study is to investigate the link between (co)morbidity and ageing by exploring biomarkers and molecular mechanisms of disease-triggered deterioration in patients with pancreatic ductal adenocarcinoma (PDAC) and (thromboembolic) ischaemic stroke (IS).

Methods and analysis

We will recruit 50 patients with PDAC, 50 patients with (thromboembolic) IS and 50 controls at Rostock University Medical Center, Germany. We will gather routine blood data, clinical performance measurements and patient-reported outcomes at up to seven points in time, alongside in-depth transcriptomics and proteomics at two of the early time points. Aiming for clinically relevant biomarkers, the primary outcome is a composite of probable sarcopenia, clinical performance (described by ECOG Performance Status for patients with PDAC and the Modified Rankin Scale for patients with stroke) and quality of life. Further outcomes cover other aspects of morbidity such as cognitive decline and of comorbidity such as vascular or cancerous events. The data analysis is comprehensive in that it includes biostatistics and machine learning, both following standard role models and additional explorative approaches. Prognostic and predictive biomarkers for interventions addressing senescence may become available if the biomarkers that we find are specifically related to ageing/cellular senescence. Similarly, diagnostic biomarkers will be explored. Our findings will require validation in independent studies, and our dataset shall be useful to validate the findings of other studies. In some of the explorative analyses, we shall include insights from systems biology modelling as well as insights from preclinical animal models. We anticipate that our detailed study protocol and data analysis plan may also guide other biomarker exploration trials.

Ethics and dissemination

The study was approved by the local ethics committee (Ethikkommission an der Medizinischen Fakultät der Universität Rostock, A2019-0174), registered at the German Clinical Trials Register (DRKS00021184), and results will be published following standard guidelines.
Mutations inZP4are associated with abnormal zona pellucida and female infertility
Authors: Wei Xiaoli , Li Youzhu , Liu Qicai , Liu Wensheng , Yan Xiaohong , Zhu Xingshen , Zhou Dekun , Tian Yingpu , Zhang Fuxing , Li Na , Lu Zhongxian
Published: January 2021

Background

The zona pellucida (ZP) of human oocytes plays essential protective roles in sperm–egg interactions during fertilisation and embryo development.ZP4-null female rabbits exhibit a thin and irregular ZP, which severely impairs embryo development and fertility. However, the effects ofZP4defect on human female reproduction remain unknown.

Methods and results

We performed whole-exome sequencing in 26 female patients with abnormal (thin and irregular) ZP and identified heterozygous variants inZP4(OMIM: 613514) from 3 patients (approximately 11%). NoZP4variant was found in the 30 control women with proven fertility. We constructedZP4-mutated plasmids and found that the variants reduced the secretion of ZP4 in vitro. Lower suction pressure facilitated egg retrieval, and intracytoplasmic sperm injection (ICSI) was a desirable treatment forZP4-mutated patients with abnormal ZP.

Conclusions

We identifiedZP4as a novel gene for human abnormal ZP and found that lower suction pressure and ICSI are efficient treatment strategies.
Apolipoprotein L1 risk genotypes in Ghanaian patients with systemic lupus erythematosus: a prospective cohort study
Authors: Blazer Ashira , Dey Ida Dzifa , Nwaukoni Janet , Reynolds Margaret , Ankrah Festus , Algasas Huda , Ahmed Tasneem , Divers Jasmin
Published: January 2021

Objective

Two apolipoprotein L1 (APOL1) risk variants (RV) are enriched in sub-Saharan African populations due to conferred resistance toTrypanosoma brucei. These variants associate with adverse renal outcomes by multiple causes including SLE. Despite emerging reports that SLE is common in Ghana, whereAPOL1variant allelic frequencies are high, the regional contribution to SLE outcomes has not been described. Accordingly, this prospective longitudinal cohort study tested the associations betweenAPOL1high-risk genotypes and kidney outcomes, organ damage accrual and death in 100 Ghanaian patients with SLE.

Methods

This was a prospective cohort study of 100 SLE outpatients who sought care at Korle bu Teaching Hospital in Accra, Ghana. Adult patients who met 4 American College of Rheumatology criteria for SLE were genotyped for APOL1 and followed longitudinally for SLE activity as measured by the Safety of Estrogens in Lupus National Assessment-Systemic Lupus Erythematosus Disease Activity Index (SELENA-SLEDAI) hybrid and organ injury as measured by the Systemic Lupus International Collaborating Clinics Damage Index (SDI) at baseline and every 6 months for 1 year. Outcomes of interest were kidney function, SDI and case fatality.

Results

Assuming a recessive inheritance, theAPOL1high-risk genotype (2RV) associated with end-stage renal disease (ESRD) at an OR of 14 (p=0.008). These patients accrued more SDI points particularly in renal and neurological domains. The SDI was 81.3% higher in 2RV patients compared with 0RV or 1RV patients despite no difference in SLE activity (p=0.01). After a 12-month period of observation, 3/12 (25%) of the 2RV patients died compared with 2/88 (2.3%) of the 0RV or 1RV carriers (OR=13.6, p=0.01). Deaths were due to end-stage kidney disease and heart failure.

Conclusion

APOL1RVs were heritable risk factors for morbidity and mortality in this Ghanaian SLE cohort. Despite no appreciable differences in SLE activity,APOL1high-risk patients exhibited progressive renal disease, organ damage accrual and a 13-fold higher case fatality.
Male or female genital cutting: why ‘health benefits’ are morally irrelevant
Authors: Earp Brian D
Published: January 2021

The WHO, American Academy of Pediatrics and other Western medical bodies currently maintain that all medically unnecessary female genital cutting of minors is categorically a human rights violation, while either tolerating or actively endorsing medically unnecessary male genital cutting of minors, especially in the form of penile circumcision. Given that some forms of female genital cutting, such as ritual pricking or nicking of the clitoral hood, are less severe than penile circumcision, yet are often performed within the same families for similar (eg, religious) reasons, it may seem that there is an unjust double standard. Against this view, it is sometimes claimed that while female genital cutting has ‘no health benefits’, male genital cutting has at least some. Is that really the case? And if it is the case, can it justify the disparate treatment of children with different sex characteristics when it comes to protecting their genital integrity? I argue that, even if one accepts the health claims that are sometimes raised in this context, they cannot justify such disparate treatment. Rather, children of all sexes and genders have an equal right to (future) bodily autonomy. This includes the right to decide whether their own ‘private’ anatomy should be exposed to surgical risk, much less permanently altered, for reasons they themselves endorse when they are sufficiently mature.
The physical and chemical limnology of Yukon’s largest lake, Lhù’ààn Mân’ (Kluane Lake), prior to the 2016 ‘A’ą̈y Chù’ diversion
Authors: McKnight Ellorie A. , Swanson Heidi , Brahney Janice , Hik David S.
Published: January 2021

Despite increasing evidence that large northern lakes are rapidly changing due to climate change, descriptive baseline studies of their physicochemical properties are largely lacking, limiting our ability to detect or predict change. This study represents a comprehensive scientific assessment of the limnology of Yukon’s largest lake: Lhù’ààn Mân’ (Kluane Lake), an important waterbody for local and First Nation communities, and key habitat for trout and salmon. Water sample and instrument data generated throughout 2015 describe distinct regions within the lake and their respective seasonal variability. A deep, glacially-influenced southern basin was characterized by cold, turbid, poorly stratified, unproductive, and nutrient-poor conditions; a shallower northwestern region (Tthe Kaala Daagur (Brooks/Little Arm)) was warmer, fully mixed, and more productive; a northeast region (’Ùha K’ènji (Talbot/Big Arm)) was clear and stratified with intermediate depth, temperature, productivity, and nutrient concentrations; and a central region had intermediate physicochemical conditions relative to the other three. This variability demonstrates the need for adequate spatial (within lake) and temporal (between seasons) monitoring of large northern lakes. In 2016, glacier recession within the watershed resulted in diversion of the lake’s primary inflow (‘A’ą̈y Chù’ (Slims River)). Our results, when used together with Indigenous knowledge, form a historical reference that enables assessments of the potential ecological consequences to Lhù’ààn Mân’.
Elevated temperature and deposited sediment jointly affect early life history traits in southernmost Arctic char populations
Authors: Mari Lisandrina , Daufresne Martin , Guillard Jean , Evanno Guillaume , Lasne Emilien
Published: January 2021

The combination of global warming and local stressors can have dramatic consequences on freshwater biota. Sediment deposition is an important pressure that can affect benthic species and benthic ontogenetic stages (eggs and larvae) habitat quality. However, knowledge on the effects of sediment in a warming context is lacking. We used a common garden approach to examine the effects of combined exposure to elevated temperature and deposited sediment on early life history traits in offspring of four wild Arctic char (Salvelinus alpinus) populations, originating from geographically isolated lakes at the southern edge of the species range. We report interactive effects of temperature and sediment, with higher temperature exacerbating the negative effects of sediments on the duration of the incubation period and on the body size – yolk expenditure trade-off during development. Our results highlight that reevaluating the impacts of sediment on organisms under the lens of global warming and at the scale of several wild populations is needed to improve our understanding of how vulnerable species can respond to environmental changes.
Fabrication, characterization and analysis of a prototype high purity germanium detector for $$^{76}$$Ge-based neutrinoless double beta decay experiments
Authors: Jany A. , Misiaszek M. , Mroz T. , Panas K. , Zuzel G. , Wojcik M. , Brudecki K. , Jurkowski J. , Mietelski J. W. , Misiak R. , Marszałek M. , Mitura-Nowak M.
Published: January 2021

Experiments searching for the neutrinoless double beta decay in $$^{76}$$

76

Ge are currently achieving the lowest background level and, in connection with the excellent energy resolution of germanium detectors, they exhibit the best discovery potential for the decay. Expansion to a ton scale of the active target mass is presently considered – in this case on-site production of the detectors may be an option. In this paper we describe the fabrication and characterization procedures of a prototype detector with a small p+ contact, which enhances the abilities of the pulse shape discrimination – one of the most important tools for background reduction. Simulations of the shapes of pulses from the detector were carried out and tuned, taking the advantage of the fact that all the parameters of the Ge crystal, cryostat and of the spectroscopic chain were known. As a result, the pulse shape analyses performed on the simulated and measured data agree very well. The worked out method allows to optimize geometry and crystal parameters in terms of pulse shape analysis efficiency, before the actual production of the detectors.
Direct detection of dark matter: Precision predictions in a simplified model framework
Authors: Borschensky Christoph , Coniglio Gabriele , Jäger Barbara , Jochum Josef , Schipperges Vincent
Published: January 2021

We present a calculation of the next-to-leading order QCD corrections for the scattering of Dark Matter particles off nucleons in the framework of simplified models with s- and t-channel mediators. These results are matched to the Wilson coefficients and operators of an effective field theory that is generally used for the presentation of experimental results on spin-independent and spin-dependent direct detection rates. Detailed phenomenological studies illustrate the complementary reach of collider searches for Dark Matter and the direct detection experiments CRESST and XENON. In the case of cancellation effects in the tree-level contributions, one-loop corrections can have a particularly large impact on exclusion limits in the case of combined $$s + t$$

s
+
t

-channel models.
Radiative three-body D-meson decays in and beyond the standard model
Authors: Adolph Nico , Brod Joachim , Hiller Gudrun
Published: January 2021

We study radiative charm decays $$D \rightarrow P_1 P_2 \gamma $$

D
→

P
1

P
2

γ

, $$P_{1,2}=\pi ,K$$

P

1
,
2

=
π
,
K

in QCD factorization at leading order and within heavy hadron chiral perturbation theory. Branching ratios including resonance contributions are around $$\sim 10^{-3}$$

∼

10

-
3

for the Cabibbo-favored modes into $$K \pi \gamma $$

K
π
γ

and $$\sim 10^{-5}$$

∼

10

-
5

for the singly Cabibbo-suppressed modes into $$\pi ^+ \pi ^- \gamma , K^+ K^- \gamma $$

π
+

π
-

γ
,

K
+

K
-

γ

, and thus in reach of the flavor factories BES III and Belle II. Dalitz plots and forward–backward asymmetries reveal significant differences between the two QCD frameworks; such observables are therefore ideally suited for a data-driven identification of relevant decay mechanisms in the standard-model dominated $$D \rightarrow K \pi \gamma $$

D
→
K
π
γ

decays. This increases the potential to probe new physics with the $$D \rightarrow \pi ^+ \pi ^- \gamma $$

D
→

π
+

π
-

γ

and $$D \rightarrow K^+ K^- \gamma $$

D
→

K
+

K
-

γ

decays, which are sensitive to enhanced dipole operators. CP asymmetries are useful to test the SM and look for new physics in neutral $$|\Delta C|=1$$

|
Δ
C
|
=
1

transitions. Cuts in the Dalitz plot enhance the sensitivity to new physics due to the presence of both s- and t, u-channel intermediate resonances.
Note on shape moduli stabilization, string gas cosmology and the swampland criteria
Authors: Mitchell Gabrielle A. , Brandenberger Robert
Published: January 2021

In String Gas Cosmology, the simplest shape modulus fields are naturally stabilized by taking into account the presence of string winding and momentum modes. We determine the resulting effective potential for these fields and show that it obeys the de Sitter conjecture, one of the swampland criteria for effective field theories to be consistent with superstring theory.
Introduction, generation and entanglement of entangled displaced even and odd squeezed states
Authors: Karimi Amir
Published: January 2021

In this paper, first, we introduce special types of entangled quantum states named “entangled displaced even and odd squeezed states” by using displaced even and odd squeezed states which are constructed via the action of displacement operator on the even and odd squeezed states, respectively. Next, we present a theoretical scheme to generate the introduced entangled states. This scheme is based on the interaction between a [Formula: see text]-type three-level atom and a two-mode quantized field in the presence of two strong classical fields. In the continuation, we consider the entanglement feature of the introduced entangled states by evaluating concurrence. Moreover, we study the influence of the displacement parameter on the entanglement degree of the introduced entangled states and compare the results. It will be observed that the concurrence of the “entangled displaced odd squeezed states” has less decrement with respect to the “entangled displaced even squeezed states” by increasing the displacement parameter.
Stable wormhole models in general relativity under conformal symmetry
Authors: Ashraf Asifa , Zhang Zhiyue
Published: January 2021

In this study, we shall explore conformal symmetry to examine the wormhole models by considering traceless fluid. In this regard, we shall take anisotropic fluid with spherically symmetric space-time. Further, we shall calculate the properties of shape-functions, which are necessary for the existence of wormhole geometry. The presence of exotic matter is confirmed in all the cases through the violation of the Null Energy Condition. Furthermore, we have discussed the stability of wormhole solutions through the Tolman–Oppenheimer–Volkoff (TOV) equation. It is observed that our acquired solutions are stable under the particular values of involved parameters in different cases in conformal symmetry.
On the Randić matrix and Randić energy
Authors: Hatefi H. , Ahangar H. Abdollahzadeh , Khoeilar R. , Sheikholeslami S. M.
Published: January 2021

Let [Formula: see text] be a graph with [Formula: see text] vertices, and let [Formula: see text] be the degree of the vertex [Formula: see text] in the graph [Formula: see text]. The Randić matrix of [Formula: see text] is the square matrix of order [Formula: see text] whose [Formula: see text]-entry is equal to [Formula: see text] if the vertex [Formula: see text] and the vertex [Formula: see text] of [Formula: see text] are adjacent, and [Formula: see text] otherwise. The Randić eigenvalues of [Formula: see text] are the eigenvalues of its Randić matrix and the Randić energy of [Formula: see text] is the sum of the absolute values of its Randić eigenvalues. In this paper, we obtain some new results for the Randić eigenvalues and the Randić energy of a graph.
Synthesis and characterization of strontium-doped barium titanate thin film by dip and dry technique
Authors: Chavan S. G. , Tarale A. N. , Salunkhe D. J.
Published: January 2021

Thin films of polycrystalline (Ba[Formula: see text][Formula: see text]TiO3 ([Formula: see text] = 0.2 and 0.3) with Perovskite structure were prepared by a dip and dry technique on a platinum-coated silicon substrate. The good quality thin films with uniform microstructure and thickness were successfully produced by dip-coating techniques annealed at 730[Formula: see text]C for 1 h. The resulting thin film shows a well-developed dense polycrystalline structure with more uniform grain size distribution. The BST thin films were characterized for their structural, Raman spectroscopy, morphological properties, and complex impedance properties. The dielectric constant-frequency curve showed the good dielectric constant and loss dielectric loss with low-frequency dispersion. The BST 0.3 thin film reveals that the dielectric constant and dielectric loss at a frequency of 1 kHz were 578 and 0.02, respectively. The obtained results on dielectric properties can be analyzed in terms of the Maxwell–Wagner model.
Kreon
Authors: Papagiannis Anastasios , Saloustros Giorgos , Xanthakis Giorgos , Kalaentzis Giorgos , Gonzalez-Ferez Pilar , Bilas Angelos
Published: January 2021

Persistent key-value stores have emerged as a main component in the data access path of modern data processing systems. However, they exhibit high CPU and I/O overhead. Nowadays, due to power limitations, it is important to reduce CPU overheads for data processing.

In this article, we propose
Kreon
, a key-value store that targets servers with flash-based storage, where CPU overhead and I/O amplification are more significant bottlenecks compared to I/O randomness. We first observe that two significant sources of overhead in key-value stores are: (a) The use of compaction in Log-Structured Merge-Trees (LSM-Tree) that constantly perform merging and sorting of large data segments and (b) the use of an I/O cache to access devices, which incurs overhead even for data that reside in memory. To avoid these,
Kreon
performs data movement from level to level by using partial reorganization instead of full data reorganization via the use of a full index per-level.
Kreon
uses memory-mapped I/O via a custom kernel path to avoid a user-space cache.

For a large dataset,
Kreon
reduces CPU cycles/op by up to 5.8×, reduces I/O amplification for inserts by up to 4.61×, and increases insert ops/s by up to 5.3×, compared to RocksDB.
The Non-psychopath's Guide to Managing an Open-source Project
Authors: Neville-Neil George V.
Published: January 2021

Transitioning from one of the technical faithful to one of the hated PHBs (pointy-haired bosses), whether in the corporate or the open-source world, is truly a difficult transition. Unless you are a type who has always been meant for the C-suite?, it's going to take a lot of work and a lot of patience, mostly with yourself, to make this transition. Doing something "for the good of (blank)" usually means you are sublimating your own needs to the needs of others, and if you don't acknowledge that, you are going to get smacked and surprised by your own reactions to people very, very quickly.
High Performance NiOx Extended-Gate Field-Effect Transistor Biosensor for Detection of Uric Acid
Authors: Pan Tung-Ming , Lin Chen-Hung
Published: January 2021

In this paper, we developed a high performance NiOx extended-gate field-effect transistor (EGFET) biosensor for detection of uric acid. The structural and sensing properties of the NiOx sensing film deposited on a n+-type Si substrate was examined for an EGFET pH sensor. X-ray diffraction, atomic force microscope and X-ray photoelectron spectroscopy were used to analyze the film features of the NiOx sensing film. The NiOx sensing film based on EGFET exhibited a high pH sensitivity of 58.53 mV pH−1, a small hysteresis voltage of 1.4 mV and a low drift rate of 0.30 mV h−1. Moreover, the NiOx EGFET biosensor showed a high linearity in the uric acid range between 1 and 30 mg dl−1. In addition, this NiOx EGFET biosensor demonstrated a very good selectivity to uric acid over other interfering substrates (ascorbic acid, glucose, urea).
In Situ X-ray Absorption Spectroscopy to Monitor the Degradation of Fe/N/C Cathode Catalyst in Proton Exchange Membrane Fuel Cells
Authors: Nabae Y. , Yuan Q. , Nagata S. , Kusaba K. , Aoki T. , Takao N. , Itoh T. , Arao M. , Imai H. , Higashi K. , Sakata T. , Uruga T. , Iwasawa Y.
Published: January 2021

Understanding the degradation mechanism of Fe/N/C cathode catalysts in proton exchange membrane fuel cells (PEMFCs) is important. We studied the degradation of an Fe/N/C catalyst prepared from polyimide nanoparticles in an in situ cell by X-ray absorption spectroscopy (XAS). This technique enables real-time monitoring of the Fe species during a fuel cell operation. The Fe K-edge absorption spectra were recorded during the continuous operation of the fuel cell. Initially during the fuel cell operation, the Fe species were atomically isolated and their valence state was found to be 3+. The spectra gradually changed during the first few hours of operation, suggesting the dissolution of the Fe species from the active sites, whereas the fuel cell performance continued to decrease during the eight hours of operation. The demetallation from the FeN
x
centers during the first few hours has been successfully monitored in real time, while the remaining FeN
x
centers seem to be stable in the following fuel cell operating condition.
Long-Term Effects of Humidity on Stainless Steel Pitting in Sea Salt Exposures
Authors: Srinivasan J. , Weirich T. D. , Marino G. A. , Annerino A. R. , Taylor J. M. , Noell P. J. , Griego J. J. M. , Schaller R. F. , Bryan C. R. , Locke J. S. , Schindelholz E. J.
Published: January 2021

Ground 304 stainless steel (SS) samples were exposed to sea salt particles at 35 °C and two relative humidity (RH) levels for durations ranging from 1 week to 2 years. For all exposure times, pit number density and total pit volume at 40% RH were observed to be considerably greater than those at 76% RH. Statistical analysis of distributions of pit populations for both RH conditions showed that pit number density and total pit volume increased rapidly at first but slowed as exposure time increased. Cross-hatched features were observed in the 40% RH pits while ellipsoidal, faceted pits were observed at 76% RH. Optical profilometry indicated that most pits were not hemispherical. X-ray tomography provided evidence of undercutting and fissures. Piecewise curve fitting modeled the 40% RH data closely, predicting that corrosion damage would eventually plateau. However, a similar treatment of the 76% RH data suggested that corrosion damage would continuously increase, which implied that the piecewise power-law fit was limited in its ability to model atmospheric corrosion generally. Based on these observations, the operative mechanisms determining long-term corrosion behavior were hypothesized to be different depending on the RH of exposure.
The Cathodic Behavior of Aluminum from Pt/Al2O3 Catalysts in Molten LiF-AlF3-CaF2 and Implications for Metal Recovery from Spent Catalysts
Authors: Padamata Sai Krishna , Yasinskiy Andrey S. , Polyakov Peter V.
Published: January 2021

Electrochemical behaviour of aluminium ions from the Pt/γ-Al2O3 spent catalyst in the eutectic [LiF (63.6 wt.%)–AlF3 (36.4 wt.%)]eutectic−5 wt.% CaF2 melt was studied by the means of cyclic voltammetry, chronopotentiometry and chronoamperometry methods. Tungsten rod (diameter 2 mm) was used as a working electrode. The XRD method was used to study the composition of melt collected near the working electrode and the spent catalyst. The aluminium reduction kinetics was studied concerning varying parameters like spent catalyst content in the melt and the temperature. The reduction of Al3+ ions on the tungsten electrode changed from diffusion-controlled to quasi-reversible process. The charge transfer coefficient and the diffusion coefficient were calculated from the data obtained from the above-mentioned methods. The estimated diffusion activation energy was 117.85 kJ.mole−1.
Spectroelectrochemical Behavior of Cr, Fe, Co, and Ni in LiCl-KCl Molten Salt for Decontaminating Radioactive Metallic Wastes
Authors: Yoon Seokjoo , Choi Sungyeol
Published: January 2021

This study examines the thermodynamic, kinetic, and spectroscopic behaviors of Cr, Fe, Co, and Ni to lay the foundation to develop an electrochemical decontamination process for radioactive metallic wastes. Cyclic voltammetry combined with numerical fitting was used to obtain the formal potentials, standard rate constants, and diffusion coefficients of redox reactions, Cr(II)/Cr, Fe(II)/Fe(0), Co(II)/Co(0), and Ni(II)/Ni(0), in LiCl-KCl at 773 K. The order of the diffusion coefficients was 10–5cm2s−1, which agrees with the existing data and the standard rate constants showed similar values with the order of 10–3cm s−1between experimental correlations and numerical fitting. UV–vis-NIR absorption spectroscopy of the metallic constituents was performed to derive molar absorption coefficients and molecular structures in molten salt media. In particular, the redox reaction of Cr(III)/Cr(II) was investigated by chronoabsorptometry to obtain its formal potential, the number of electrons, and the diffusion coefficient of Cr(II). The obtained reaction properties were used in the numerical modeling of the ECE reaction in a Ni and Co binary system to reproduce the experimental results of CV, revealing the presence of chemical reaction. The findings of this study will be directly used for designing a decontamination process to produce acceptable waste forms and reduce waste volume.
Improving Performance and Durability of Low Temperature Direct Ammonia Fuel Cells: Effect of Backpressure and Oxygen Reduction Catalysts
Authors: Wang Teng , Zhao Yun , Setzler Brian. P. , Yan Yushan
Published: January 2021

Low temperature direct ammonia fuel cells (DAFCs) are attractive for transportation applications. The primary obstacle to their commercial use is their low performance and poor durability. In the present work, we focus on improving DAFCs performance and durability by examining the effect of operating backpressure and oxygen reduction reaction (ORR) catalysts such as Acta 4020, Pd/C and Pt/C. DAFCs with Acta 4020 cathode can reach a peak power density of 390 mW cm−2 which is among the best reported performance, but they can be operated for a period of 11 h at 300 mA cm−2. DAFCs with Pd/C cathode offer a moderate performance with a peak power density of 304 mW cm−2, but has a much improved durability - a continuous operation for up to 36 h with a slow decay rate of ∼1 mV h−1 at 300 mA cm−2. In addition, the degradation pathways for DAFCs with Pd/C cathode are probed by characterizing the initial and final electrodes by XPS, suggesting that cathodic Pd dissolution occurs during the durability test.
An update on brown adipose tissue biology: a discussion of recent findings
Authors: Gaspar Rafael C. , Pauli José R. , Shulman Gerald I. , Muñoz Vitor R.
Published: January 2021

Brown adipose tissue (BAT) has been encouraged as a potential treatment for obesity and comorbidities due to its thermogenic activity capacity and contribution to energy expenditure. Some interventions such as cold and β-adrenergic drugs are able to activate BAT thermogenesis as well as promote differentiation of white adipocytes into brown-like cells (browning), enhancing the thermogenic activity of these cells. In this mini-review, we discuss new mechanisms related to BAT and energy expenditure. In this regard, we will also discuss recent studies that have revealed the existence of important secretory molecules from BAT “batokines” that act in autocrine, paracrine, and endocrine mechanisms, which in turn may explain some of the beneficial roles of BAT on whole body glucose and fat metabolism. Finally, we will discuss new insights related to BAT thermogenesis with an additional focus on the distinct features of BAT metabolism between rodents and humans.