bluuebunny/crossref_metadata_2025_split huggingface dataset:
Broadband, silicon photonic, optical add–drop filters with 3  dB bandwidths up to 11  THz
Authors: Hammood Mustafa , Mistry Ajay , Yun Han , Ma Minglei , Lin Stephen , Chrostowski Lukas , Jaeger Nicolas A. F. 
Published: May 2021

We present the designs, theory, and experimental demonstrations of ultra-broadband, optical add–drop filters on the silicon-on-insulator platform, realized using period-chirped contra-directional couplers. Our fabricated devices have ultra-broad 3 dB bandwidths of up to 11 THz (88.1 nm), with flat-top responses at their drop ports. All of our devices were fabricated using a commercial, CMOS-compatible, 193 nm deep-ultraviolet lithography process. By using lithography-prediction models, the measured bandwidths, insertion losses, central wavelengths, and extinction ratios of our devices are all in good agreement with our predicted, simulated results. Such filters are necessary for photonic integrated circuits to operate over multiple optical bands.
Efficient point-by-point Bragg grating inscription in sapphire fiber using femtosecond laser filaments
Authors: Xu Xizhen , He Jun , He Jia , Xu Baijie , Chen Runxiao , Wang Ying , Yang Yatao , Wang Yiping 
Published: May 2021

Sapphire fiber Bragg gratings (SFBGs) inscribed by using femtosecond laser point-by-point (PbP) technology typically have an extremely low reflectivity due to the limited cross-sectional area of refractive index modulations (RIMs) created in sapphire fiber. Hence, we propose and experimentally demonstrate a filamentation process for fabricating PbP SFBGs. This approach provides an efficient method for producing SFBGs at various Bragg wavelengths with a higher reflectivity, since the filament tracks could enlarge the cross-sectional area of RIMs. The influences of the pulse energy and the focal depth on the generation and morphology of the filament tracks were studied, and after optimizing these parameters, high-quality filament tracks with a length of 90 µm and a width of 1.4 µm were produced into sapphire fiber with a diameter of 100 µm. These filament tracks were precisely assembled in sapphire fiber, generating an SFBG with a reflectivity of 2.3%. The total fabrication time for this SFBG only requires

∼

1.1

s

. Subsequently, a wavelength-division-multiplexed (WDM) SFBG array consisting of five SFBGs was efficiently constructed. Moreover, the high-temperature response of the SFBG array was investigated and the experimental results showed that the SFBG array can withstand a high temperature of 1600°C. Such a WDM SFBG array could serve as quasi-distributed high-temperature sensor which will be promising in many areas, i.e., metallurgical, chemical, and aviation industries.
Hollow-core fiber photothermal methane sensor with temperature compensation
Authors: Zhao Pengcheng , Ho Hoi Lut , Jin Wei , Fan Shangchun , Gao Shoufei , Wang Yingying 
Published: May 2021

We demonstrate a high sensitivity all-fiber spectroscopic methane sensor based on photothermal interferometry. With a 2.4-m-long anti-resonant hollow-core fiber, a 1654 nm distributed feedback laser, and a Raman fiber amplifier, a noise-equivalent concentration of

∼

4.3

p
p
b

methane is achieved at the room temperature and pressure of

∼

1

b
a
r

. The effects of temperature on the photothermal phase modulation as well as the stability of the interferometer are studied. By introducing a temperature-dependent compensation factor and stabilizing the interferometer at quadrature, signal instability of

∼

2.1

%

is demonstrated for temperature variation from 296 to 373 K.
Endocystectomy as a conservative surgical treatment for hepatic cystic echinococcosis: A systematic review with single-arm meta-analysis
Authors: Al-Saeedi Mohammad , Ramouz Ali , Khajeh Elias , El Rafidi Ahmad , Ghamarnejad Omid , Shafiei Saeed , Ali-Hasan-Al-Saegh Sadeq , Probst Pascal , Stojkovic Marija , Weber Tim Frederik , Hoffmann Katrin , Mehrabi Arianeb 
Published: May 2021

Background
In patients with hepatic cystic echinococcosis (CE), treatment effectiveness, outcomes, complications, and recurrence rate are controversial. Endocystectomy is a conservative surgical approach that adequately removes cyst contents without loss of parenchyma. This conservative procedure has been modified in several ways to prevent complications and to improve surgical outcomes. This systematic review aimed to evaluate the intraoperative and postoperative complications of endocysectomy for hepatic CE as well as the hepatic CE recurrence rate following endocystectomy.

Methods
A systematic search was made for all studies reporting endocystectomy to manage hepatic CE in PubMed, Web of Science, and Cochrane CENTRAL databases. Study quality was assessed using the methodological index for non-randomized studies (MINORS) criteria and the Cochrane revised tool to assess risk of bias in randomized trials (RoB2). The random-effects model was used for meta-analysis and the arscine-transformed proportions were used to determine complication-, mortality-, and recurrence rates. This study is registered with PROSPERO (number CRD42020181732).

Results
Of 3,930 retrieved articles, 54 studies reporting on 4,058 patients were included. Among studies reporting preoperative anthelmintic treatment (31 studies), albendazole was administered in all of them. Complications were reported in 19.4% (95% CI: 15.9–23.2; I2 = 84%; p-value <0.001) of the patients; biliary leakage (10.1%; 95% CI: 7.5–13.1; I2 = 81%; p-value <0.001) and wound infection (6.6%; 95% CI: 4.6–9; I2 = 27%; p-value = 0.17) were the most common complications. The post-endocystectomy mortality rate was 1.2% (95% CI: 0.8–1.8; I2 = 21%; p-value = 0.15) and the recurrence rate was 4.8% (95% CI: 3.1–6.8; I2 = 87%; p-value <0.001). Thirty-nine studies (88.7%) had a mean follow-up of more than one year after endocystectomy, and only 14 studies (31.8%) had a follow-up of more than five years.

Conclusion
Endocystectomy is a conservative and feasible surgical approach. Despite previous disencouraging experiences, our results suggest that endocystectomy is associated with low mortality and recurrence.
Long-term impact of a ten-year intervention program on human and canine Trypanosoma cruzi infection in the Argentine Chaco
Authors: Cardinal Marta Victoria , Enriquez Gustavo Fabián , Macchiaverna Natalia Paula , Argibay Hernán Darío , Fernández María del Pilar , Alvedro Alejandra , Gaspe María Sol , Gürtler Ricardo Esteban 
Published: May 2021

Background
Interruption of domestic vector-borne transmission of Trypanosoma cruzi is still an unmet goal in several American countries. In 2007 we launched a long-term intervention program aimed to suppress house infestation with the main domestic vector in southern South America (Triatoma infestans) and domestic transmission in Pampa del Indio, a resource-constrained, hyperendemic municipality with 1446 rural houses inhabited by Creole and indigenous people, in the Argentine Chaco ecoregion. Here, we assessed whether the 10-year insecticide-based program combined with community mobilization blocked vector-borne domestic transmission of T. cruzi to humans and dogs.

Methods
We carried out two municipality-wide, cross-sectional serosurveys of humans and dogs (considered sentinel animals) during 2016–2017 to compare with baseline data. We used a risk-stratified random sampling design to select 273 study houses; 410 people from 180 households and 492 dogs from 151 houses were examined for antibodies to T. cruzi using at least two serological methods.

Results
The seroprevalence of T. cruzi in children aged <16 years was 2.5% in 2017 (i.e., 4- to 11-fold lower than before interventions). The mean annual force of child infection (λ) sharply decreased from 2.18 to 0.34 per 100 person-years in 2017. One of 102 children born after interventions was seropositive for T. cruzi; he had lifetime residence in an apparently uninfested house, no outside travel history, and his mother was T. cruzi-seropositive. No incident case was detected among 114 seronegative people of all ages re-examined serologically. Dog seroprevalence was 3.05%. Among native dogs, λ in 2016 (1.21 per 100 dog-years) was 5 times lower than at program onset. Six native adult dogs born after interventions and with stable lifetime residence were T. cruzi-seropositive: three had exposure to T. infestans at their houses and one was an incident case.

Conclusions
These results support the interruption of vector-borne transmission of T. cruzi to humans in rural Pampa del Indio. Congenital transmission was the most likely source of the only seropositive child born after interventions. Residual transmission to dogs was likely related to transient infestations and other transmission routes. Sustained vector control supplemented with human chemotherapy can lead to a substantial reduction of Chagas disease transmission in the Argentine Chaco.
Determinants of pregnancy-induced hypertension on maternal and foetal outcomes in Hossana town administration, Hadiya zone, Southern Ethiopia: Unmatched case-control study
Authors: Babore Getachew Ossabo , Aregago Tsegaye Gebre , Ermolo Tadesse Lelago , Nunemo Mangistu Handiso , Habebo Teshome Tesfaye 
Published: May 2021

BackgroundGlobally, 292,982 women die due to the complications of pregnancy and childbirth per year, out of those deaths 85% occurs in Sub Saharan Africa. In Ethiopia, pre-eclampsia accounts for 11% of direct maternal deaths.ObjectiveTo determine maternal and foetal outcomes of pregnancy-induced hypertension among women who gave birth at health facilities in Hossana town administration.MethodsInstitutional based unmatched case-control study was conducted among women, who gave birth at health facilities from May 20 to October 30, 2018. By using Epi-Info version 7; 207 sample size was estimated, for each case two controls were selected. Two health facilities were selected using a simple random sampling method. Sample sizes for each facility were allocated proportionally. All cleaned & coded data were entered into Epi-info version 3.5.1 and analysis was carried out using SPSS version 20. Multivariate analysis was performed to determine predictors of pregnancy-induced hypertension at a p-value of <0.05.ResultWomen between 18 to 41 years old had participated in the study with the mean age of 26.00(SD ±4.42), and 25.87(SD ±5.02) for cases and controls respectively. Out of participants 21(30.4%) among cases and 21(15.2%) among controls had developed at least one complication following delivery. 12 (17.4%) and 8 (5.7%) foetal deaths were found in cases and controls groups respectively whereas 15.6% from cases and 3.6% from controls groups women gave birth to the foetus with intra-uterine growth retardation. Women gravidity AOR = 0.32 [95% CI (0.12 0.86)], Previous history of pregnancy-induced hypertension AOR = 22.50 [95% CI (14.95 16.52)] and educational status AOR = 0.32[95% CI (0.12, 0.85)] were identified as predictor of pregnancy-induced hypertension.ConclusionWomen with a previous history of pregnancy-induced hypertension had increased risk of developing pregnancy-induced hypertension, whilst ≥ 3 previous pregnancies and informal educational status decrease odds of developing pregnancy-induced hypertension.
Micro- and macro-borderless surgery using a newly developed high-resolution (4K) three-dimensional video system
Authors: Yagi Shintaro , Ito Takashi , Shirai Hisaya , Yao Siyuan , Masano Yuki , Ogawa Eri , Gabata Ryosuke , Uemoto Shinji , Kobayashi Eiji 
Published: May 2021

Objective
Microsurgery using conventional optical microscopes or surgical loupes features a limited field of view and imposes a serious strain on surgeons especially during long surgeries. Here we advocate the micro- and macro-borderless surgery (MMBS) using a novel high-resolution (4K) three-dimensional (3D) video system. This study aimed to confirm the applicability of this concept in several surgical procedures.

Methods
We evaluated the possible use and efficacy of MMBS in the following experiments in porcine subjects. Experiment 1 (non-inferiority test) consisted of dissection and anastomosis of carotid artery, portal vein, proper hepatic artery, and pancreatoduodenectomy with surgical loupe versus MMBS. Experiment 2 (feasibility test) consisted of intra-abdominal and intra-thoracic smaller arteries anastomosed by MMBS as a pre-clinical setting. Experiment 3 (challenge on new surgery) consisted of orthotopic liver transplantation of the graft from a donor after circulatory death maintained by machine perfusion. Circulation of the cardiac sheet with a vascular bed in experiment 2 and liver graft during preservation in experiment 3 was evaluated with indocyanine green fluorescence imaging equipped with this system.

Results
Every procedure was completed by MMBS. The operator and assistants could share the same field of view in heads-up status. The focal depth was deep enough not to be disturbed by pulsing blood vessels or respiratory movement. The tissue circulation could be evaluated using fluorescence imaging of this system.

Conclusions
MMBS using the novel system is applicable to various surgeries and valuable for both fine surgical procedures and high-level surgical education.
Predicting patients with false negative SARS-CoV-2 testing at hospital admission: A retrospective multi-center study
Authors: Ghazi Lama , Simonov Michael , Mansour Sherry G. , Moledina Dennis G. , Greenberg Jason H. , Yamamoto Yu , Biswas Aditya , Wilson F. Perry 
Published: May 2021

Importance
False negative SARS-CoV-2 tests can lead to spread of infection in the inpatient setting to other patients and healthcare workers. However, the population of patients with COVID who are admitted with false negative testing is unstudied.

Objective
To characterize and develop a model to predict true SARS-CoV-2 infection among patients who initially test negative for COVID by PCR.

Design
Retrospective cohort study.

Setting
Five hospitals within the Yale New Haven Health System between 3/10/2020 and 9/1/2020.

Participants
Adult patients who received diagnostic testing for SARS-CoV-2 virus within the first 96 hours of hospitalization.

Exposure
We developed a logistic regression model from readily available electronic health record data to predict SARS-CoV-2 positivity in patients who were positive for COVID and those who were negative and never retested.

Main outcomes and measures
This model was applied to patients testing negative for SARS-CoV-2 who were retested within the first 96 hours of hospitalization. We evaluated the ability of the model to discriminate between patients who would subsequently retest negative and those who would subsequently retest positive.

Results
We included 31,459 hospitalized adult patients; 2,666 of these patients tested positive for COVID and 3,511 initially tested negative for COVID and were retested. Of the patients who were retested, 61 (1.7%) had a subsequent positive COVID test. The model showed that higher age, vital sign abnormalities, and lower white blood cell count served as strong predictors for COVID positivity in these patients. The model had moderate performance to predict which patients would retest positive with a test set area under the receiver-operator characteristic (ROC) of 0.76 (95% CI 0.70–0.83). Using a cutpoint for our risk prediction model at the 90th percentile for probability, we were able to capture 35/61 (57%) of the patients who would retest positive. This cutpoint amounts to a number-needed-to-retest range between 15 and 77 patients.

Conclusion and relevance
We show that a pragmatic model can predict which patients should be retested for COVID. Further research is required to determine if this risk model can be applied prospectively in hospitalized patients to prevent the spread of SARS-CoV-2 infections.
The influence on oxidative stress markers, inflammatory factors and intestinal injury-related molecules in Wahui pigeon induced by lipopolysaccharide
Authors: Wang Fei , Liu Jin , Hu Xiaofen , Zhong Youbao , Wen Feng , Tang Xiaoen , Yang Shanshan , Zhong Shengwei , Zhou Zuohong , Yuan Xu , Li Yong 
Published: May 2021

IntroductionThe intestinal structure is the foundation for various activities and functions in poultry. An important question concerns the changes in the intestinal status under endotoxin stimulation. This study aimed to investigate the mechanism of intestinal injury induced by lipopolysaccharide (LPS) in Wahui pigeons.MethodsThirty-six 28-day-old healthy Wahui pigeons were randomly divided into two groups. The experimental group was injected with LPS (100 μg/kg) once per day for five days, and the control group was treated with the same amount of sterile saline. Blood and the ileum were collected from pigeons on the first, third, and fifth days of the experiment and used for oxidative stress assessment, inflammatory factor detection, histopathological examination, and positive cell localization. In addition, intestinal injury indices and mRNA expression levels (tight junction proteins, inflammatory cytokines, and factors related to autophagy and apoptosis) were evaluated.ResultsVilli in the ileum were shorter in the LPS group than in the control group, and D-lactic acid levels in the serum were significantly increased. Glutathione and catalase levels significantly decreased, but the malondialdehyde content in the serum increased. TNF-α and IL-10 were detected at higher levels in the serum, with stronger positive signals and higher mRNA expression levels, in the LPS group than in the control group. In addition, the levels of TLR4, MyD88, NF-κB, and HMGB1 in the inflammatory signaling pathway were also upregulated. Finally, the mRNA expression of Claudin3, Occludin, and ZO-1 was significantly decreased; however, that of Beclin1 and Atg5 was increased in the LPS group.ConclusionIleal pathological changes and oxidative stress were caused by LPS challenge; it is proposed that this triggering regulates the inflammatory response, causing excessive autophagy and apoptosis, promoting intestinal permeability, and leading to intestinal injury in Wahui pigeons.
Clinical profile and factors associated with COVID-19 in Yaounde, Cameroon: A prospective cohort study
Authors: Fouda Mbarga Nicole , Epee Emilienne , Mbarga Marcel , Ouamba Patrick , Nanda Herwin , Nkengni Aristide , Guekeme Joseph , Eyong Justin , Tossoukpe Sylvie , Noumedem Sosso Sauvia , Ngono Ngono Engelbert , Ntsama Lazare Mbala , Bonyomo Landry , Tchatchoua Patrick , Vogue Noel , Metomb Steve , Ale Franck , Ousman Moussa , Job Dorian , Moussi Charlotte , Tamakloe Modeste , Haberer Jessica E. , Ndeso Atanga Sylvester , Halle-Ekane Gregory , Boum Yap 
Published: May 2021

Background
A year after the COVID-19 pandemic started, there are still few scientific reports on COVID-19 in Africa. This study explores the clinical profiles and factors associated with COVID-19 in Cameroon.

Materials and methods
In this prospective cohort study, we followed patients admitted for suspicion of COVID-19 at Djoungolo Hospital between 01st April and 31st July 2020. Patients were categorised by age groups and disease severity: mild (symptomatic without clinical signs of pneumonia), moderate (with clinical signs of pneumonia without respiratory distress) and severe cases (clinical signs of pneumonia and respiratory distress not requiring invasive ventilation). Demographic information and clinical features were summarised. Multivariable analysis was performed to predict risk.

Findings
A total of 313 patients were admitted during the study period; 259 were confirmed cases of COVID-19 by Polymerase Chain Reaction (PCR). Among the confirmed cases, the male group aged 40 to 49 years (13.9%) was predominant. Disease severity ranged from mild (26.2%; n = 68) to moderate (59%; n = 153) to severe (14.7%; n = 38); the case fatality rate was 1% (n = 4). Dysgusia (46%; n = 119) and hyposmia/anosmia (37.8%; n = 98) were common features of COVID-19. Nearly one-third of patients had comorbidities (29%; n = 53), of which hypertension was the most common (18.9%; n = 49). Participation in mass gatherings (Odds Ratio (OR) = 2.37; P = 0.03) and dysgusia (OR = 2.09, P = 0.02) were predictive of diagnosis of COVID-19. Age groups 60 to 69 (OR = 7.41; P = 0.0001), 50 to 59 (OR = 4.09; P = 0.03), 40 to 49 (OR = 4.54; P = 0.01), male gender (OR = 2.53; P = 0.04), diabetes (OR = 4.05; P = 0.01), HIV infection (OR = 5.57; P = 0.03), lung disease (OR = 6.29; P = 0.01), dyspnoea (OR = 3.70; P = 0.008) and fatigue (OR = 3.35; P = 0.02) significantly predicted COVID-19 severity.

Conclusions
Most COVID-19 cases in this study were benign with low fatality. Age (40–70), male gender, HIV infection, lung disease, dyspnoea and fatigue are associated with severe COVID-19. Such findings may guide public health decision-making.
Retinal oxygen saturation changes progressively over time in diabetic retinopathy
Authors: Hardarson Sveinn Hakon , Stefánsson Einar , Bek Toke 
Published: May 2021

Purpose
According to cross-sectional studies, oxygen saturation is elevated in retinal vessels in diabetic patients. We evaluated how retinal oxygenation (metabolic marker), vessel diameters and retinopathy grade (structural markers) change over time in diabetic patients.

Design
Prospective cohort study following screening in a hospital setting.

Methods
Retinal oximetry images were acquired in 214 patients with the Oxymap T1 oximeter. Imaging was repeated after a median of 3.0 years (range 0.76–6.8 years). Oxygen saturation and vessel diameters were measured in the right eye. Semiquantitative grading of retinopathy according to international guidelines and red lesion count were performed on fundus photographs.

Results
Retinopathy grade according to the international semiquantitative grading system was unchanged. Arteriolar saturation increased by 0.75±0.15 percentage points per year of follow-up (p<0.0001). Venular saturation increased by 1.74±0.26 percentage points per year (p<0.0001) and arteriovenous difference decreased by 0.99±0.20 percentage points per year (p<0.0001). Arteriolar diameters decreased by 2.7±8.5μm (p<0.0001) between visits and venular diameters decreased by 2.4±9.1μm (p = 0.0002). Median increase in red lesion count between visits was 2 lesions (range -128 to 212 lesions, p<0.0001). The change in red lesion count and change in diameters did not correlate with the length of follow-up (p>0.44).

Conclusions
Oxygen saturation in larger retinal vessels can increase and arteriovenous difference can decrease over time in diabetic patients without any observable changes in retinopathy grade. The results suggest that changes in retinal oxygen saturation may precede progression of diabetic retinopathy or that oxygen saturation is more sensitive to disease progression than retinopathy grade.
Lower Gastrointestinal Bleeding Associated With Sodium Polystyrene Sulfonate Use
Authors: Dantas Eduardo , Coelho Mariana , Sequeira Cristiana , Santos Inês , Martins Cláudio , Cardoso Cláudia , Freire Ricardo , Oliveira Ana Paula 
Published: May 2021

ABSTRACT
Sodium polystyrene sulfonate (kayexalate) is a cation-exchange resin widely used in the management of hyperkalemia. Gastrointestinal adverse events are uncommon; symptoms are nonspecific, and mucosal injury can range from mild ulceration to bowel perforation. An 81-year-old man was admitted because of decompensation of cirrhosis with acute kidney injury and hyperkalemia, treated with sodium polystyrene sulfonate. During admission, he presented multiple episodes of hematochezia, accompanied by tachycardia and hemoglobin drop. Colonoscopy revealed colonic ulceration, and histopathological findings were compatible with ulceration due to kayexalate injury. Despite rare, the widespread use of sodium polystyrene sulfonate puts a large population at risk of serious complications related to its use.