bluuebunny/crossref_metadata_2025 huggingface dataset:
Robert Lowell, the New Critics, and the “Unforgivable Landscape” of Liberalism
Authors: Foley Hugh
Published: January 2021

This essay argues that Robert Lowell’s poetry demonstrates a critical engagement with the liberal individual that he is not often given credit for. By examining Lowell’s handling of the pathetic fallacy, whereby the external landscape is made to match the mood of the observer, the essay reveals a critique of the historical formation of American individualism, visible in how Lowell connects the literary historical tropes he is employing to the history of American “imperial” violence. This is first shown through a close reading of “Mouth of the Hudson.” The essay connects Lowell’s view to those of his New Critical mentors, such as John Crowe Ransom, for whom the individual of the liberal political order is entwined with the history of Puritan iconoclasm and Romantic views of the poetic subject. It argues that Ransom’s critique parallels those of later critics, such as Marjorie Perloff, David Antin, and Maria Damon, who see Lowell’s poetic self as both solipsistic and symptomatic of an American liberal ideology. Demonstrating that Lowell’s views were formed by a critique of liberal individualism, it then attempts to show how Lowell moved beyond this in his later work, harnessing a depiction of the poetic subject’s individual experience to a critique of individualism itself as manifested in the American political worldview of the Cold War era. It reads “Beyond the Alps” as a demonstration of the way Lowell is able to wed both critique and depiction of individuality together through a self-aware handling of the poetic landscape.
Thermal robustness of biomechanical processes
Authors: Olberding Jeffrey P. , Deban Stephen M.
Published: January 2021

Temperature influences many physiological processes that govern life as a result of the thermal sensitivity of chemical reactions. The repeated evolution of endothermy and widespread behavioral thermoregulation in animals highlight the importance of elevating tissue temperature to increase the rate of chemical processes. Yet, movement performance that is robust to changes in body temperature has been observed in numerous species. This thermally robust performance appears exceptional in light of the well-documented effects of temperature on muscle contractile properties, including shortening velocity, force, power and work. Here, we propose that the thermal robustness of movements in which mechanical processes replace or augment chemical processes is a general feature of any organismal system, spanning kingdoms. The use of recoiling elastic structures to power movement in place of direct muscle shortening is one of the most thoroughly studied mechanical processes; using these studies as a basis, we outline an analytical framework for detecting thermal robustness, relying on the comparison of temperature coefficients (Q10 values) between chemical and mechanical processes. We then highlight other biomechanical systems in which thermally robust performance that arises from mechanical processes may be identified using this framework. Studying diverse movements in the context of temperature will both reveal mechanisms underlying performance and allow the prediction of changes in performance in response to a changing thermal environment, thus deepening our understanding of the thermal ecology of many organisms.
Pakistan’s First Child & Adolescent Psychiatry Inpatient Unit: Characteristics of admitted patients and response to treatment over a 7-year period
Authors: Imran Nazish , Bodla Zubair Hassan , Asif Aftab , Shoukat Rabia , Azeem. Muhammad Waqar
Published: January 2021

Background & Objective: Child & adolescent mental health needs to be considered as an integral component of overall health, however significant gaps exist in service provision especially inpatient services in Pakistan. The paper presents the characteristics of admitted youths and response to treatment in Pakistan’s first dedicated child & adolescent psychiatry inpatient unit in Lahore over a period of first seven years. The aim of this study was to better understand the various characteristics of children and youth admitted to this inpatient unit and response to treatment over a seven years’ period since the inception of the unit.

Methods: Inpatient medical records of children & adolescents admitted to dedicated Child & Adolescent Inpatient Unit at King Edward Medical University, Lahore were reviewed. Data was extracted regarding referral patterns, sociodemographic factors and diagnosis for the first seven years, from 2012 to 2019. Patients’ scores on Strengths and Difficulties Questionnaire and Clinical Global Impressions Scales administered during intake were also reviewed.

Results: Six hundred and thirty-four (634) patients, 56% (355) being females were admitted to the unit during seven years with mean age of 12.3±2.3. Mean duration of admission was 15.60±6.3 days. Most predominant ICD-10 Axis-I psychiatric diagnosis were neurotic, stress related and somatoform disorders (262); mood disorders (78); schizophrenia, schizotypal & delusional disorders (77) and behavioral and emotional disorders with onset usually occurring in childhood and adolescence (44). One hundred and fifty-nine (25%) children had comorbid diagnosis of intellectual disability on Axis-III. Strengths and difficulties questionnaire scores were in abnormal range for significant proportion (>50 %) of patients. CGI mean scores showed marked improvement at discharge.

Conclusion: Neurotic, stress related and somatoform disorders are the most common diagnosis in youth needing inpatient treatment in Pakistani setup. Study results indicate that there is a clear need for specialized inpatient child and adolescent services such as ours in low- & middle-income countries.

doi: https://doi.org/10.12669/pjms.37.2.2611

How to cite this:Imran N, Bodla ZH, Asif A, Shoukat R, Azeem MW. Pakistan’s First Child & Adolescent Psychiatry Inpatient Unit: Characteristics of admitted patients and response to treatment over a 7-year period. Pak J Med Sci. 2021;37(2):305-311.  doi: https://doi.org/10.12669/pjms.37.2.2611

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Quantitative Analyses of Skin Cancer Research in Pakistan
Authors: Rehman Syeda Hajrah , Majid Bushra , Syed Sofia Ali , Qureshi Muhammad Asif
Published: January 2021

In order to investigate the current status of skin cancer research output in Pakistan, International (PubMed) and national (PakMediNet) scientific databases were searched using variety of keywords to retrieve relevant publications. A strict inclusion criterion was applied to select skin cancer publications for final analyses. Data were recorded by two authors and consistent data were entered into SPSS and Microsoft Excel and analyzed for annual growth rate and frequencies. Of 116 articles that were finally included in the study, 74 were original articles, 24 were case-reports, 10 were review articles, three were editorials, two were research communications and one each of case-series, correspondence and response to letter to the editor. The first article on skin cancer from Pakistan was published in 1976 whereas the last article included in our study was published in December 2018. Excluding Karachi, most of the cities have no contribution in the field of skin cancer. Since 1976 to date, the average number of publications per year has been low, with only 2.7 publications per year. Skin cancer research is alarmingly scarce in Pakistan. This calls for immediate attention by all concerned to contribute and devise appropriate measures towards skin cancer research in Pakistan.

doi: https://doi.org/10.12669/pjms.37.2.2889

How to cite this:Rehman SH, Majid B, Syed SA, Qureshi MA. Quantitative Analyses of Skin Cancer Research in Pakistan. Pak J Med Sci. 2021;37(2):582-587. doi: https://doi.org/10.12669/pjms.37.2.2889

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Upper extremity musculoskeletal disorders and exposure to Ergonomic risk factors among handicraft workers
Authors: Mahmood Wajeeha , Bashir Muhammad Salman , Ehsan Sarah , Qureshi Muhammad Atif
Published: January 2021

Objective: To determine the association of Upper extremity musculoskeletal disorders and Exposure to Ergonomic risk factors among handicraft workers.

Methods: This cross-sectional survey was conducted in a 12 weeks’ duration i.e. from November 2018 till January 2019. Nordic musculoskeletal questionnaire was used to determine the frequency of upper limb musculoskeletal disorders. Postural analysis was done using Rapid Upper Limb Assessment (RULA). Data was collected from 100 Handicraft workers and the type of work included Art work (n=18), Ada Work (n=7), botanical arrangement (n=11), Textile, fashion designing and stitching (n=38), Fine arts (n=20), embroidery and knitting (n=6).

Results: The frequency distribution of Rapid upper limb assessment (RULA) score for exposure to risk factors showed that 47 participants were at a high risk and required implementation of change. Most of the participants (n=35) reported pain in neck and shoulder (n=29). The chi square test for association between pain in upper extremity and exposure to risk factors showed that only wrist pain had statistically significant association with overall RULA score (p-value<0.05).

Conclusion: The study concluded that neck and shoulder are more frequently affected among handicraft workers. The frequency of workers who were at high ergonomic risk and required implementation of change in working conditions was high.

doi: https://doi.org/10.12669/pjms.37.2.749

How to cite this:Mahmood W, Bashir MS, Ehsan S, Qureshi MA. Upper extremity musculoskeletal disorders and exposure to Ergonomic risk factors among handicraft workers. Pak J Med Sci. 2021;37(2):494-498. doi: https://doi.org/10.12669/pjms.37.2.749`

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
A recall-by-genotype study on polymorphisms in the TMPRSS6 gene and oral iron absorption: a study protocol
Authors: Jallow Momodou W. , Campino Susana , Prentice Andrew M. , Cerami Carla
Published: January 2021

Background: Oral iron supplementation is commonly used to treat and prevent anaemia. The transmembrane protease serine 6 gene (TMPRSS6), which encodes matriptase 2, is a negative regulator of hepcidin, the key controller of iron homeostasis. Genome-wide association studies (GWAS) have identified several single nucleotide polymorphisms (SNPs) in the TMPRSS6 gene that are associated with an increased risk of iron-deficiency anaemia.  We will investigate the in vivo effects of three previously reported TMPRSS6 variants (rs855791, rs4820268 and rs2235321) on oral iron absorption in non-anaemic volunteers in The Gambia.

Methods: A recall-by-genotype study design will be employed. Pre-genotyped participants will be recruited from the West African BioResouce (WABR), which currently contains over 3000 genotyped individuals. Male and female volunteers will be selected based on polymorphisms (rs855791, rs4820268 and rs2235321) in the TMPRSS6 gene in the Gambian population. The effects of a single variant allele at one SNP and the additive effect of two or three variant alleles from either two or all three SNPs will be investigated. Study participants will be given a single oral dose of 400mg ferrous sulfate, and blood samples will be collected at baseline, two hours and five hours post supplementation. Differences in iron absorption between genotype groups will be assessed by measuring the increase in serum iron concentration at five hours post iron ingestion.

Discussion: This study will increase understanding of the role of genetic variations in TMPRSS6 on oral iron absorption in subjects of West African origin. This will test for the biological basis for the association of each of the three TMPRSS6 variants with iron absorption. This may help in guiding future iron intervention strategies, particularly in populations with a high frequency of these SNPs and a high frequency of anaemia.

Study registration: ClinicalTrials.gov NCT03341338 14/11/17.
The diagnosis of tuberculous meningitis in adults and adolescents: protocol for a systematic review and individual patient data meta-analysis to inform a multivariable prediction model
Authors: Boyles Tom , Stadelman Anna , Ellis Jayne P. , Cresswell Fiona V. , Lutje Vittoria , Wasserman Sean , Tiffin Nicki , Wilkinson Robert
Published: January 2021

Background: Tuberculous meningitis (TBM) is the most lethal and disabling form of tuberculosis. Delayed diagnosis and treatment, which is a risk factor for poor outcome, is caused in part by lack of availability of diagnostic tests that are both rapid and accurate. Several attempts have been made to develop clinical scoring systems to fill this gap, but none have performed sufficiently well to be broadly implemented. We aim to identify and validate a set of clinical predictors that accurately classify TBM using individual patient data (IPD) from published studies.

Methods: We will perform a systematic review and obtain IPD from studies published from the year 1990 which undertook diagnostic testing for TBM in adolescents or adults using at least one of, microscopy for acid-fast bacilli, commercial nucleic acid amplification test for Mycobacterium tuberculosis or mycobacterial culture of cerebrospinal fluid.  Clinical data that have previously been shown to be associated with TBM, and can inform the final diagnosis, will be requested. The data-set will be divided into training and test/validation data-sets for model building. A predictive logistic model will be built using a training set with patients with definite TBM and no TBM. Should it be warranted, factor analysis may be employed, depending on evidence for multicollinearity or the case for including latent variables in the model.

Discussion: We will systematically identify and extract key clinical parameters associated with TBM from published studies and use a ‘big data’ approach to develop and validate a clinical prediction model with enhanced generalisability. The final model will be made available through a smartphone application. Further work will be external validation of the model and test of efficacy in a randomised controlled trial.
Alleviating Drug Shortages: The Role of Mandated Reporting Induced Operational Transparency
Authors: Lee Junghee , Lee Hyun Seok (Huck) , Shin Hyoduk , Krishnan Vish
Published: January 2021

The ongoing shortage of pharmaceutical drugs critically threatens public health. With increasing industry consolidation, operational disruptions at a firm can lead to a nationwide shortage of life-saving drugs. In 2012, the U.S. Food and Drug Administration mandated all manufacturers to report any manufacturing interruption that can potentially cause shortages. The goal of the mandate was to mitigate drug shortages by enhancing operational transparency in the pharmaceutical industry. Subsequently, other countries such as Canada have also begun mandating reporting of interruptions to alleviate drug shortages. We leverage the policy changes in the United States and Canada to understand the impact of mandated reporting induced operational transparency on alleviating the extent of drug shortages. Using the data on time-to-recovery for individual drug-shortage incident and annual-days-of-shortage for each drug, we find that the new policy alleviates drug shortages, but its effectiveness is contingent upon the prevailing level of competition in the product category. Although the intervention is not as impactful under a monopoly, the mandate is most effective under a duopoly, and its impact wanes as competition intensifies. In the absence of the mandate-induced transparency, competition does not necessarily alleviate shortages, but with the regulation, competition can relieve drug shortages. Our results potentially offer healthcare providers and policymakers the impetus to alleviate drug shortages by mandating interruption reporting and improving operational transparency.

This paper was accepted by Charles Corbett, operations management.
Effect of PTH treatment on bone healing in insufficiency fractures of the pelvis: a systematic review
Authors: Bovbjerg Pernille , Høgh Ditte , Froberg Lonnie , Schmal Hagen , Kassem Moustapha
Published: January 2021

The aging of our society is associated with an increasing number of insufficiency fractures of the pelvis and the current standard of care is pain control and early mobilization. The aim of this study was to explore whether parathyroid hormone (PTH) treatment can support bone healing in these patients. We conducted a systematic review searching the databases PubMed, Embase and Cochrane. Our primary outcome was fracture healing, secondary outcome measures comprised pain, mobility and patient-reported outcome measures (PROMs). Eight articles were included in the qualitative synthesis, of which two were included in a meta-analysis. However, only three studies were comparative including one randomized controlled trial. Fracture healing and reported pain were assessed after eight weeks, and were significantly improved in the group being treated with PTH (p < 0.01) in the meta-analysis. All articles described a positive effect for PTH on fracture healing and pain. Our systematic review indicates that there is a positive effect of PTH treatment on healing and pain in patients with insufficiency fracture in the pelvic ring, but further research is necessary.

Cite this article: EFORT Open Rev 2021;6:9-14. DOI: 10.1302/2058-5241.6.200029
Humeral shaft fractures
Authors: Gallusser Nicolas , Barimani Bardia , Vauclair Frédéric
Published: January 2021

Humeral shaft fractures are relatively common, representing approximately 1% to 5% of all fractures. Conservative management is the treatment of choice for most humeral shaft fractures and offers functional results and union rates that are not inferior to surgical management. Age and oblique fractures of the proximal third are risk factors for nonunion. Surgical indication threshold should be lower in patients older than 55 years presenting with this type of fracture. Functional outcomes and union rates after plating and intramedullary nailing are comparable, but the likelihood of shoulder complications is higher with intramedullary nailing. There is no advantage to early exploration of the radial nerve even in secondary radial nerve palsy.

Cite this article: EFORT Open Rev 2021;6:24-34. DOI: 10.1302/2058-5241.6.200033
Full endoscopic surgery for thoracic pathology: an assessment of supportive evidence
Authors: Gibson Rory D. S. , Wagner Ralf , Gibson J. N. Alastair
Published: January 2021

In the last five years, surgeons have applied endoscopic transforaminal surgical techniques mastered in the lumbar spine to the treatment of thoracic pathology. The aim of this systematic review was to collate the available literature to determine the place and efficacy of full endoscopic approaches used in the treatment of thoracic disc prolapse and stenosis. An electronic literature search of PubMed, Embase, the Cochrane database and Google Scholar was performed as suggested by the Preferred Reporting Items for Systematic Review and Meta-analysis statements. Included were any full-text articles referring to full endoscopic thoracic surgical procedures in any language. We identified 17 patient series, one cohort study and 13 case reports with single or of up to three patients. Although the majority included disc pathology, 11 papers related cord compression in a proportion of cases to ossification of the ligamentum flavum or posterior longitudinal ligament. Two studies described the treatment of discitis and one reported the use of endoscopy for tumour resection. Where reported, excellent or good outcomes were achieved for full endoscopic procedures in a mean of 81% of patients (range 46–100%) with a complication rate of 8% (range 0–15%), comparing favourably with rates reported after open discectomy (anterior, posterolateral and thoracoscopic) or by endoscopic tubular assisted approaches. Twenty-one of the 31 author groups reported use of local anaesthesia plus sedation rather than general anaesthesia, providing ‘self-neuromonitoring’ by allowing patients to respond to cord and/or nerve stimuli.

Cite this article: EFORT Open Rev 2021;6:50-60. DOI: 10.1302/2058-5241.6.200080
The Classification of Documents in Malay and Indonesian Using the Naive Bayesian Method Uses Words and Phrases as a Training Set
Authors: Wijaya Marvin Chandra
Published: January 2021

Malay Language and Indonesian Language are two closely related languages, sharing a lot in common in the meanings of words and grammar. Classifying the two languages automatically using a tool is a challenge because the two languages are very similar. The classification method that is widely used today is the Naive Bayesian method. This method needs to be implemented in a particular way to increase the level of classification accuracy. In this study, a new method was used, by using a training set in the form of words and phrases instead of just using a training set in the form of words only. With this method, the level of classification accuracy of the two languages is increased.
Phase Transition as an Emergent Phenomenon Analysed by Violation of Structural Invariant (M, BM)
Authors: Bila Jiri , Reshak Ali H , Chysky Jan
Published: January 2021

When modeling complex systems, we usually encounter the following difficulties: partiality, large amounts of data and uncertainty of conclusions. The most common approach used for modeling is the physical approach, sometimes reinforced by statistical procedures. If we assume emergences in the complex system, a physical approach is not appropriate at all. Instead, we build here the approach of structural invariants. In this paper, we show that another plane can be built above the plane of physical description, which is responsible for violation of structural invariants. Main attention is concentrated (in this article) on the invariant matroid and bases of matroid (M, BM) in combination with Ramsey graph theory. In addition, the article introduces a calculus that describes the emergent phenomena using two quantities - the power of the emergent phenomenon and the complexity of the structure of the considered complex system. We show the application of the method for modeling phase transition in chemistry.
Clinical Care of COVID-19 Patients in a Front-line ICU
Authors:   HonorHealth Scottsdale Osborn Medical Center, Scottsdale, AZ USA, Raschke Robert , Glenn Tyler , Josen Kim
Published: January 2021

No abstract available. Article truncated after 150 words. These are some clinical observations made after over the past 10 months, working in a busy COVID-19 ICU unit in Scottsdale, AZ. The opinions expressed here are those of the private practice authors. Overview of triage and rounding on large numbers of COVID-19 patients in the ICU service. Our approach to bedside care of our ICU service has required abbreviation for the sake of efficiency in the face of more than a doubling of our census. Our approach to rounding is opinion-based. We’ve been forced to cut corners where we can in order to survive. Our hospital uses the Abbott ID-Now® rapid point-of -are test for screening all COVID-19-asymptomatic patients admitted to our hospital, but due to its low sensitivity in hospitalized patients (1). We do not trust it to rule-out COVID-19 in patients with pneumonia being admitted to the ICU and also order an in-house PCR for such patients …
Measurement of morphology thickness and refractive index in a melanoma A375 cell line using digital holographic microscopy
Authors: Palacios-Ortega Natalith , Hernández-Montes María del Socorro , Mendoza-Santoyo Fernando , Flores-Moreno Jorge Mauricio
Published: January 2021

Digital holographic microscopy (DHM) is a technique that has high potential for analyzing biological samples and has been successfully applied to the study of cells and cell lines providing information about important parameters such as refractive index, morphology, and dry mass, among others; it has also found applicability to study the effects of therapeutic treatments. Finding the size and shape of cells is important since they tend to change in the presence of some pathologies. In this research work, we obtain the morphology thickness and refractive index of the A375 melanoma cell line through a slight tilting of the cell in a DHM setup. Further, the development of a novel mathematical expression based on this tilt and in the optical phase difference is presented. We show images of melanoma cells with the refractive index information included, and their morphology thickness as rendered from the holographic phase maps recorded with DHM.
High-resolution coded aperture optimization for super-resolved compressive x-ray cone-beam computed tomography
Authors: Mojica Edson , Correa Claudia V. , Arguello Henry
Published: January 2021

Compressive x-ray cone-beam computed tomography (CBCT) approaches rely on coded apertures (CA) along multiple view angles to block a portion of the x-ray energy traveling towards the detectors. Previous work has shown that designing CA patterns yields improved images. Most designs, however, are focused on multi-shot fan-beam (FB) systems, handling a 1:1 ratio between CA features and detector elements. In consequence, image resolution is subject to the detector pixel size. Moreover, CA optimization for computed tomography involves strong binarization assumptions, impractical data rearrangements, or computationally expensive tasks such as singular value decomposition (SVD). Instead of using higher-resolution CA distributions in a multi-slice system with a more dense detector array, this work presents a method for designing the CA patterns in a compressive CBCT system under a super-resolution configuration, i.e., high-resolution CA patterns are designed to obtain high-resolution images from lower-resolution projections. The proposed method takes advantage of the Gershgorin theorem since its algebraic interpretation relates the circle radii with the eigenvalue bounds, whose minimization improves the condition of the system matrix. Simulations with medical data sets show that the proposed design attains high-resolution images from lower-resolution detectors in a single-shot CBCT scenario. Besides, image quality is improved in up to 5 dB of peak signal-to-noise compared to random CA patterns for different super-resolution factors. Moreover, reconstructions from Monte Carlo simulated projections show up to 3 dB improvements. Further, for the analyzed cases, the computational load of the proposed approach is up to three orders of magnitude lower than that of SVD-based methods.
Effect of workpiece curvature on the tool influence function during hemispherical sub-aperture tool glass polishing
Authors: Suratwala T. , Menapace J. , Tham G. , Steele R. , Wong L. , Ray N. , Bauman B. , Gregory M. , Hordin T.
Published: January 2021

The influence of workpiece curvature on the tool influence function
spot during polishing of fused silica glass with cerium oxide slurry,
while using a rotating hemispherical pad-foam tool for a wide variety
of process conditions (tool displacement, inclination angle, and
rotation rate), has been investigated. (Workpiece curvature ranged
from 500 mm radius concave to 43 mm radius convex.) The TIF spot
decreases in diameter and increases in the peak removal rate on more
convex workpieces. In contrast, the TIF spot increases both in
diameter and peak removal rate on more concave workpieces. For the
range of workpiece curvatures investigated, both the spot size and the
peak removal rate changed significantly, as much as 2 times. An
elastic sphere–sphere contact mechanics model, which utilizes both a
modified displacement (that leads to a change in the applied load) as
well as a mismatch factor (that influences the pressure distribution
shape), has been developed. The model was validated using both offline
load-displacement measurements and finite-element analysis
simulations. The model quantitatively describes the measured change in
the relative contact diameter and relative pressure distribution, as
well as semiquantitively describes the change in the relative
volumetric removal rate on a large variety of TIF spots. The change in
the volumetric removal rate for convex workpieces is a result of the
balance between a decreasing spot size (reducing removal) and an
increasing peak pressure (increasing removal), which usually results
in relatively small changes in volumetric removal. In the case of
concave workpieces, the volumetric removal rate change is also
governed by a similar balance, but the spot size increase contribution
dominates, resulting in a significant increase in volumetric removal
rate. Understanding these trends can enable methods to add greater
determinism during the fabrication of freeform optics by adjusting
polishing parameters (such as dwell time) while the tool translates
along a workpiece surface with different local curvatures.
Non-uniformity calibration method of space-borne area CCD for directional polarimetric camera
Authors: Yao Pingping , Tu Bihai , Xu Sunlong , Yu Xinyu , Xu Zhilong , Luo Donggen , Hong Jin
Published: January 2021

The directional polarimetric camera (DPC) is a polarization sensor with the characteristics of ultra-wide-angle and low-distortion imaging. The multi-angle polarization information is helpful to obtain the spatial distribution of target radiation, and multiple data fusion relies on the non-uniformity calibration of image plane. The non-uniformity consists of many factors such as lens, detector assembly, spatial stray light, etc. The single correction method can not distinguish the error source effectively. In consideration of the in-flight operation mode of DPC based on the adjustment of exposure time, the non-uniformity correction method of the detector based on multi parameters is proposed. Through the electro-optical performance measurement system of the CCD detector, the sensitive factors such as temperature, dark current, exposure time and spectral response are obtained. After a series of preprocessing of the image including removal of dark signal, removal of smearing effect and temperature compensation, the non-uniformity calibration based on multi-parameters is imposed on the detector. The low-frequency unbalanced response difference of the image surface is eliminated, and the high-frequency difference is effectively suppressed. The experimental results show that the photo response non-uniformity of 95% full well single frame data is reduced from 2.86% to 0.36%. After correction, the data noise is shown as shot noise, and the detector has good ability of dynamic range adjustment. The non-uniformity calibration by the proposed method can offer data support for the instrumental calibration and in-flight fast calculation, and provide effective reference for the subsequent polarization remote sensing instruments.
Grating-enabled high-speed high-efficiency surface-illuminated silicon photodiodes
Authors: Li Chong , Bao Kai , Qin Shihong , Guan Kai , Xu Gang , Su Jiale
Published: January 2021

High-speed, high-efficiency silicon photodetectors play important roles in the optical communication links that are used increasingly in data centers to handle the increasing volumes of data traffic and higher bandwidths required as use of big data and cloud computing continues to grow exponentially. Monolithic integration of the optical components with signal processing electronics on a single silicon chip is of paramount importance in the drive to reduce costs and improve performance. Here we report grating-enhanced light absorption in a silicon photodiode. The absorption efficiency is determined theoretically to be as high as 77% at 850 nm for the optimal structure, which has a thin intrinsic absorption layer with a thickness of 220 nm. The fabricated devices demonstrate a high bandwidth of 11.3 GHz and improved radio-frequency output power of more than 14 dB, thus making them suitable for use in data center optical communications.
Method for high precision measurement of decaying dynamics using attosecond wave-mixing spectroscopy
Authors: Mi Kang , Cao Wei , Xu Huiyao , Zhang Qingbin , Lu Peixiang
Published: January 2021

Ultrafast wave-mixing spectroscopies involving extreme ultraviolet (EUV) attosecond pulses provide unprecedented insight into electronic dynamics. Here, we proposed a versatile lifetime-detection method for doubly excited states with odd or even parities by mixing an attosecond EUV pulse with two few-cycle near infrared (NIR) pulses in atomic helium under a noncollinear geometry. By properly choosing the time order of the pulse sequence, the spatially resolved nonlinear signals carry significant information of the decaying dynamics of excited states, which can be utilized to retrieve the lifetimes of states with different parities in a single measurement. The validity and robustness of the method has been verified by numerical simulations based on a few-level model of helium including the spatial distribution of atoms. The accuracy of the lifetime measurement method is better than a few hundred attoseconds. It provides a powerful tool for probing decaying dynamics of the electronic wave packet with superb resolution.
Hollow waveguide-miniaturized quantum cascade laser heterodyne spectro-radiometer
Authors: Robinson Iain , Butcher Helen L. , Macleod Neil A. , Weidmann Damien
Published: January 2021

A miniature thermal infrared laser heterodyne spectro-radiometer based on hybrid optical integration is demonstrated. A quantum cascade laser emitting at 953 cm−1 (10.5 μm) is used as the local oscillator. Integration is achieved using hollow waveguides inscribed in a copper substrate, with slot-encapsulated optical components positioned to maintain fundamental hybrid mode coupling. The demonstrator performances are studied in the laboratory and show a noise level within 1.6 times of the ideal case. Atmospheric high-resolution transmittance spectroscopy of carbon dioxide and water vapor in solar occultation is demonstrated. The total column concentrations are derived as well as measurement uncertainties, 399.5 ± 2.2 ppm for CO2 and 1066 ± 62 ppm for H2O. The miniature laser heterodyne spectro-radiometer demonstration opens the prospect for nanosatellite-based high spectral resolution thermal infrared atmospheric sounding.
High performance OCTA enabled by combining features of shape, intensity, and complex decorrelation
Authors: Li Huakun , Liu Kaiyuan , Cao Tongtong , Yao Lin , Zhang Ziyi , Deng Xiaofeng , Du Chixin , Li Peng
Published: January 2021

Motion contrast optical coherence tomography angiography (OCTA) entails a precise identification of dynamic flow signals from the static background, but an intermediate region with voxels exhibiting a mixed distribution of dynamic and static scatterers is almost inevitable in practice, which degrades the vascular contrast and connectivity. In this work, the static-dynamic intermediate region was pre-defined according to the asymptotic relation between inverse signal-to-noise ratio (iSNR) and decorrelation, which was theoretically derived for signals with different flow rates based on a multi-variate time series (MVTS) model. Then the ambiguous voxels in the intermediate region were further differentiated using a shape mask with adaptive threshold. Finally, an improved OCTA classifier was built by combining shape, iSNR, and decorrelation features, termed as SID-OCTA, and the performance of the proposed SID-OCTA was validated experimentally through mouse retinal imaging.
Switchable and spacing tunable dual-wavelength spatiotemporal mode-locked fiber laser
Authors: Long Jin-Gan , Gao Yu-Xin , Lin Wei , Wu Jia-Wen , Lin Xu-Bin , Hong Wei-Yi , Cui Hu , Luo Zhi-Chao , Xu Wen-Cheng , Luo Ai-Ping
Published: January 2021

We report a switchable and spacing tunable dual-wavelength spatiotemporal mode-locked (STML) laser based on the multimode interference filtering effect in an all-fiber linear cavity. The dual-wavelength STML operations combined with different pulse patterns are achieved. By adjusting the polarization controllers, the dual-wavelength STML pulses can be switched to single wavelength operation, which is tunable up to 35 nm under certain pump powers. Moreover, the dual-wavelength spacing can also be tuned from 8 nm to 22 nm. The obtained results contribute to understanding and exploring the spatiotemporal characteristics operating in the multi-wavelength regime of STML fiber lasers. All-fiber STML lasers with lasing wavelength tunability and flexibility may have applications in the fields of optical communications and optical measurements.
Efficient frequency conversion based on resonant four-wave mixing
Authors: Cheng Chin-Yao , Liu Zi-Yu , Hu Pi-Sheng , Wang Tsai-Ni , Chien Chung-Yu , Lin Jia-Kang , Juo Jz-Yuan , Shiu Jiun-Shiuan , Yu Ite A. , Chen Ying-Cheng , Chen Yong-Fan
Published: January 2021

Efficient frequency conversion of photons has important applications in optical quantum technology because the frequency range suitable for photon manipulation and communication usually varies widely. Recently, an efficient frequency conversion system using a double-

Λ

four-wave mixing (FWM) process based on electromagnetically induced transparency (EIT) has attracted considerable attention because of its potential to achieve a nearly 100% conversion efficiency (CE). To obtain such a high CE, the spontaneous emission loss in this resonant-type FWM system must be suppressed considerably. A simple solution is to arrange the applied laser fields in a backward configuration. However, the phase mismatch due to this configuration can cause a significant decrease in CE. Here, we demonstrate that the phase mismatch can be effectively compensated by introducing the phase shift obtained by two-photon detuning. Under optimal conditions, we observe a wavelength conversion from 780 to 795 nm with a maximum CE of

91.2
%
±
0.6
%

by using this backward FWM system at an optical depth of 130 in cold

87

Rb

atoms. The current work represents an important step toward achieving low-loss, high-fidelity quantum frequency conversion based on EIT.
Continuous chirped-wave phase-sensitive optical time domain reflectometry
Authors: Jiang Jialin , Wang Zinan , Wang Zitan , Qiu Zijie , Liu Chunye , Rao Yunjiang
Published: January 2021

This Letter proposes a novel phase-sensitive optical time domain reflectometry (

Φ

-OTDR) with continuous chirped-wave (CCW), which can make full use of both time and frequency domain resources. The principle and benefits of CCW

Φ

-OTDR are elaborated. With the merit of CCW

Φ

-OTDR, 1.042 MHz sensing bandwidth and

5

p

ε

/

H
z

strain sensitivity are achieved along a 1013 m fiber with 4.4 m spatial resolution. To the best of the authors’ knowledge, this is the first time that a

Φ

-OTDR achieves megahertz sensing bandwidth with metric spatial resolution, and without limiting the frequency feature of the disturbance. The good performance in long-range sensing is also verified over a 49.7 km fiber. More than that, the digital domain flexibility of the proposed scheme can be used to optimize the measured acoustic signal according to its feature and the practical needs.
Value probability analysis for linear phase estimation in sinusoidal structured-light range imaging
Authors: Je Changsoo , Park Hyung-Min
Published: January 2021

Linear phase estimation is crucial for accuracy of sinusoidal structured-light range imaging. This Letter presents value probability analysis for a continuously differentiable function and shows that the probability of a value of the function is closely related to the derivative of the function. We apply the value probability analysis to the intensity, phase, and intermediate values in sinusoidal structured light, and we show that the probability adjustment of phase is more effective than those of other values for linear phase estimation. The phase probability adjustment is applied to synthetic and real scenarios of sinusoidal structured-light range imaging to show the effectiveness of the presented analysis and adjustment.
Structural-color nanoprinting with hidden watermarks
Authors: Li Zile , Dai Qi , Deng Liangui , Zheng Guoxing , Li Gongfa
Published: January 2021

Nanostructured metasurfaces can manipulate the spectrum and polarization of incident light at the nanoscale, which suggests a new integration of color nanoprints and polarizing-related components. Herein, we design and experimentally demonstrate a structural-color nanoprint carrying hidden watermarks, enabled with the polarization-assisted spectrum manipulation of light. Specifically, under unpolarized white light, the watermarks are concealed and a structural-color nanoprinting-image occupies the metasurface plane. Meanwhile, once linearly polarized white light is incident on the same metasurface, the hidden information can be decoded, and the same nanoprinting-image covered with watermarks appears. The proposed metasurface represents a paradigm for displaying color nanoprinting-images with or without watermarks, showing a flexible switch between the two operating modes and providing an easily camouflaged scheme for anticounterfeiting, encryption, information multiplexing, high-density optical storage, etc.
Re-shapeable double-hump Bragg-spectrum using a partial-width entrenched-core waveguide
Authors: Awad Ehab
Published: January 2021

Bragg gratings are well known with several unique characteristics that make them very crucial components in various optical systems and applications. Here, a novel partial-width entrenched core (PWEC) structure within a few-mode waveguide is demonstrated. The core of silicon-on-insulator planar waveguide is simply entrenched with nano-wide rectangular air-gaps that partially fill the core width to form a stand-alone short and uniform entrenched-core Bragg grating. The periodic perturbation of trenches to input fundamental mode couples to two guided even-modes, and in turn generates a double-hump spectrum with two closely separated Bragg wavelengths. The spectrum can be tuned over a wide wavelength range from 1 to 2 µm within the shortwave infrared band. It shows a very small induced dispersion. The trenches’ width and period are found to be very crucial in the design of double-hump spectral characteristics (e.g., Bragg wavelengths, humps bandwidths, and separation). The double-hump reflection and transmission spectra with their two modes can be simply reshaped to form new spectra such as double stop-bands within the optical communication standard bands, single wide (200 nm)/ narrow (10 nm) pass-bands, notch-bands, or ultra-wide bandwidth (530 nm) full-mirrors.
Increasing the efficiency of the intra-cavity generation of ultra-short radially polarized pulses in thin-disk resonators with grating waveguide structures
Authors: Beirow Frieder , Wahl Johannes , Hohmuth Rico , Richter Andreas , Pruß Christof , Mateo Cherry May , Graf Thomas , Ahmed Marwan Abdou
Published: January 2021

In this paper, we report on the investigation of two different approaches based on grating waveguide structures (GWS) to generate radially polarized ultra-short pulses in thin-disk laser resonators. In previously reported mode-locked thin-disk oscillators emitting radially polarized pulses, a partly reflective GWS was employed as an outcoupling element for polarization shaping. This partly reflective GWS introduced significant losses for the outcoupled radiation, resulting in a reduced optical efficiency. The aim of the investigations presented here is to explore the possibility of improving the optical efficiency by using a highly reflective GWS in different resonator configurations, which circumvents the loss port present for the partly reflective GWS. The investigations show that using a highly reflective GWS as a folding mirror of the resonator enables a significant improvement of the optical efficiency compared to the previously reported configurations.
Borrelia burgdorferi infection induces long-term memory-like responses in macrophages with tissue-wide consequences in the heart
Authors: Barriales Diego , Martín-Ruiz Itziar , Carreras-González Ana , Montesinos-Robledo Marta , Azkargorta Mikel , Iloro Ibon , Escobés Iraide , Martín-Mateos Teresa , Atondo Estibaliz , Palacios Ainhoa , Gonzalez-Lopez Monika , Bárcena Laura , Cortázar Ana R. , Cabrera Diana , Peña-Cearra Ainize , van Liempd Sebastiaan M. , Falcón-Pérez Juan M. , Pascual-Itoiz Miguel A. , Flores Juana María , Abecia Leticia , Pellon Aize , Martínez-Chantar Maria Luz , Aransay Ana M. , Pascual Alberto , Elortza Felix , Berra Edurne , Lavín José Luis , Rodríguez Héctor , Anguita Juan
Published: January 2021

Lyme carditis is an extracutaneous manifestation of Lyme disease characterized by episodes of atrioventricular block of varying degrees and additional, less reported cardiomyopathies. The molecular changes associated with the response to Borrelia burgdorferi over the course of infection are poorly understood. Here, we identify broad transcriptomic and proteomic changes in the heart during infection that reveal a profound down-regulation of mitochondrial components. We also describe the long-term functional modulation of macrophages exposed to live bacteria, characterized by an augmented glycolytic output, increased spirochetal binding and internalization, and reduced inflammatory responses. In vitro, glycolysis inhibition reduces the production of tumor necrosis factor (TNF) by memory macrophages, whereas in vivo, it produces the reversion of the memory phenotype, the recovery of tissue mitochondrial components, and decreased inflammation and spirochetal burdens. These results show that B. burgdorferi induces long-term, memory-like responses in macrophages with tissue-wide consequences that are amenable to be manipulated in vivo.
Adverse fetal and neonatal outcomes in pregnancies with confirmed Zika Virus infection in Rio de Janeiro, Brazil: A cohort study
Authors: Souza Juliana P. , Méio Maria Dalva B. B. , de Andrade Laura Medeiros , Figueiredo Mirza R. , Gomes Junior Saint Clair , Pereira Junior Jose Paulo , Brickley Elizabeth , Lopes Moreira Maria Elisabeth
Published: January 2021

Objective

To analyze adverse fetal and neonatal outcomes of Zika virus infection by the timing of infection during pregnancy. Method: Cohort study of 190 pregnancies with 193 offspring with a positive RT-PCR test for Zika virus (March/2016 to April/2017).

Results

Death or defects related to congenital Zika virus infection were identified in 37.3% of fetuses and newborns, and microcephaly in 21.4% of the newborns. The proportion of small for gestational age newborns was 21.9%. Maternal symptoms in the first trimester were significantly associated with the birth of newborns with microcephaly/cerebral atrophy, small for gestational age and with the deaths (one abortion, one stillbirth and the two neonatal deaths). Maternal infection during the second trimester was further associated with asymptomatic newborns at birth. The study showed that 58.5% of the offspring with microcephaly and / or cortical atrophy were small for gestational age, with an evident decrease in symptomatic offspring without microcephaly, 24.1%, and with only 9.1% in the asymptomatic group.

Conclusion

This study showed that the earlier the symptoms appear during gestation, the more severe the endpoints. We found a higher percentage of small for gestational age newborns exposed to Zika virus early in gestation. We also found a group of apparently asymptomatic newborns with proven Zika infection, which highlights the importance of follow up studies in this population.