bluuebunny/crossref_metadata_2025 huggingface dataset:
Application of data linkage techniques to Pacific Northwest commercial fishing injury and fatality data
Authors: Nahorniak Jasmine , Bovbjerg Viktor , Case Samantha , Kincl Laurel
Published: July 2021

Background

Commercial fishing consistently has among the highest workforce injury and fatality rates in the United States. Data related to commercial fishing incidents are routinely collected by multiple organizations which do not currently coordinate or automatically link data. Each data set has the potential to generate a more complete picture to inform prevention efforts. Our objective was to examine the utility of using statistical data linkage methods to link commercial fishing incident data when personally identifiable information is not available.

Methods

In this feasibility study, we identified true matches and discrepancies between de-identified data sets using the Python Record Linkage Toolkit. Four commercial fishing data sets from Oregon and Washington were linked: the Commercial Fishing Incident Database, the Vessel Casualty Database, the Nonfatal Injuries Database, and the Oregon Trauma Registry. The data sets each covered different date ranges within 2000–2017, containing 458, 524, 184, and 11 cases respectively. Several data linkage classifiers were evaluated.

Results

The Naïve-Bayes classifier returned the highest number of true matches between these small data sets. A total of 41 true matches and 8 close matches were identified, of which 29 were determined to be duplicates. In addition, linkage highlighted 4 records that were not commercial fishing cases from Oregon and Washington. The optimum match parameters were the date, state, vessel official number, and number of people on board.

Conclusions

Statistical data linkage enables accurate, routine matching for small de-identified injury and fatality data sets such as those in commercial fishing. It provides information needed to improve the accuracy of existing data records. It also enables expanding and sharpening details of individual incidents in support of occupational safety research.
Induced hypernatremia in patients with moderate-to-severe ARDS: a randomized controlled study
Authors: Bihari Shailesh , Prakash Shivesh , Dixon Dani L. , Cavallaro Elena , Bersten Andrew D.
Published: July 2021

Background

Induced hypernatremia and hyperosmolarity is protective in animal models of lung injury. We hypothesized that increasing and maintaining plasma sodium between 145 and 150 mmol/l in patients with moderate-to-severe ARDS would be safe and will reduce lung injury. This was a prospective randomized feasibility study in moderate-to-severe ARDS, comparing standard care with intravenous hypertonic saline to achieve and maintain plasma sodium between 145 and 150 mmol/l for 7 days (HTS group). Both groups of patients were managed with lung protective ventilation and conservative fluid management. The primary outcome was 1-point reduction in lung injury score (LIS) or successful extubation by day 7.

Results

Forty patients were randomized with 20 in each group. Baseline characteristics of severity of illness were well balanced. Patients in the HTS group had higher plasma sodium levels during the first 7 days after randomization when compared with the control group (p = 0.04). Seventy five percent (15/20) of patients in the HTS group were extubated or had ≥ 1-point reduction in LIS compared with 35% (7/20) in the control group (p = 0.02). There was also a decrease in length of mechanical ventilation and hospital length of stay in the HTS group.

Conclusion

We have shown clinical improvement in patients with moderate-to-severe ARDS following induced hypernatremia, suggesting that administration of hypertonic saline is a safe and feasible intervention in patients with moderate-to-severe ARDS. This suggests progress to a phase II study.

Clinical Trial Registration Australian and New Zealand Clinical Trials Registry (ACTRN12615001282572)
How virtual avatar experience interplays with self-concepts: the use of anthropometric 3D body models in the visual stimulation process
Authors: Park Juyeon , Ogle Jennifer Paff
Published: July 2021

We explored how viewing one’s anthropometric virtual avatar would affect the viewer’s self-body perception through the comparative evaluation of self-concepts—self-esteem and self-compassion, within the framework of allocentric lock theory. We recruited 18 female adults, aged 18–21, who identified themselves to have some level of body image concerns, and who had had no clinical treatment for their body image. Participants were randomly assigned either to the experimental or control group. The experimental group participated in both body positivity program and virtual avatar program, whereas the control group attended the body positivity program, only. The results affirmed that the body positivity program served as a psychological buffer prior to the virtual avatar stimulus. After the virtual avatar experience, the participants demonstrated self-acceptance by lowering their expectation on how they should look like. The findings from exit interviews enriched the quantitative results. This study verified the mechanism of the altered processing of the stored bodily memory by the egocentric sensory input of virtual avatars, and offered practical potential of the study outcomes to be applied in various emerging fields where novel applications of virtual 3D technology are sought, such as fashion e-commerce.
Malaria prevalence, knowledge, attitude, and practice among febrile patients attending Chagni health center, Northwest Ethiopia: a cross-sectional study
Authors: Belay Bogale , Gelana Tegenu , Gebresilassie Araya
Published: July 2021

Background

Ethiopia has achieved considerable progresses in the prevention and control of malaria in the past decades; hitherto it is a formidable health concern and socio-economic impediment. This study aimed at assessing the magnitude, knowledge, attitudes and practices towards malaria among febrile patients attending Chagni health center, northwest Ethiopia.

Methods

Health facility-based cross-sectional study was conducted to estimate the prevalence of malaria and KAP towards malaria among febrile patients at Chagni health center in Chagni Town during September 2017 to February 2018. In order to determine the magnitude of malaria, finger prick blood samples were collected and thick and thin smears were prepared and microscopically examined for the presence of malaria parasites. A pre-tested structured questionnaire was also applied to assess KAP of suspected malaria patients, attending the health center. Data were analyzed using SPSS version 20.0.

Results

Prevalence of malaria among febrile patients, who visited the sampled health facility, was 7.3%. Of these, Plasmodium falciparum, P. vivax, and mixed infections accounted for 55, 44.3 and 0.7% of the cases, respectively. This study also revealed that 97% of the respondents had ever heard about malaria and recognized it as a serious health problem. Mosquito bite was identified as the main malaria transmission. Taking drug (86.3%), use of mosquito nets (73.3%), drain stagnated water (68%), and house spay with insecticides (66%) were mentioned as the main malaria prevention methods. Mosquito net coverage and utilizations in the prior night were 98 and 75%, respectively. Indoor residual spraying (IRS) coverage was 99%, of which 77.5% of study participants’ houses have been sprayed in the last 6 months.

Conclusions

The current study revealed that prevalence of malaria among febrile illnesses in the study area was relatively low (7.3%) with a high proportion of P. falciparum. Besides, participants had adequate knowledge, encouraging attitudes, and good practices about prevention and control of malaria. However, some misconceptions on malaria disease, its transmission, and prevention have been noted that actually require due attention by the concerned stakeholders. The findings of this study could be used as important inputs for the implementation of effective malaria prevention and control methods, including community health education programs, and scaling up coverage of evidence-based interventions.
Candida species in community-acquired pneumonia in patients with chronic aspiration
Authors: Moss Benjamin J. , Musher Daniel M.
Published: July 2021

Background

When Candida species is found in a sputum culture, clinicians generally dismiss it as a contaminant. We sought to identify cases of community-acquired pneumonia (CAP) in which Candida might play a contributory etiologic role.

Methods

In a convenience sample of patients hospitalized for CAP, we screened for “high-quality sputum” by Gram stain (> 20 WBC/epithelial cell) and performed quantitative sputum cultures. Criteria for a potential etiologic role for Candida included the observation of large numbers of yeast forms on Gram stain, intracellular organisms and > 106 CFU/ml Candida in sputum. We gathered clinical information on cases that met these criteria for possible Candida infection.

Results

Sputum from 6 of 154 consecutive CAP patients had large numbers of extra- and intracellular yeast forms on Gram stain, with > 106 CFU/ml Candida albicans, glabrata, or tropicalis on quantitative culture. In all 6 patients, the clinical diagnoses at admission included chronic aspiration. Greater than 105 CFU/ml of a recognized bacterial pathogen (Streptococcus pneumoniae, Staphylococcus aureus, or Pseudomonas) or > 106 CFU/ml of other ‘normal respiratory flora’ (Lactobacillus species) were present together with Candida spp. in every case. Blood cultures yielded Candida in 2 cases, and 1,3-beta-D glucan was > 500 ng/mL in 3 of 3 cases in which it was assayed. Since all patients were treated with anti-bacterial and anti-fungal drugs, no inference about etiology can be derived from therapeutic response.

Conclusions

Candida spp. together with a recognized bacterial pathogen or normal respiratory flora may contribute to the cause of CAP in patients who chronically aspirate.
Atmospheric variables and subarachnoid hemorrhage: narrative review
Authors: Vasquez Harold E. , Prasad Lakshmi , Moscote-Salazar Luis Rafael , Agrawal Amit
Published: July 2021

Background

Stroke is a neurological emergency that tends to be the first cause of death in many countries. Atmospheric variables are strongly associated with stroke, in which subarachnoid hemorrhage (SAH) has been associated in many studies to meteorological risk factors such as air pollution, air pressure, weather changes, and ambient temperature. These characteristics may influence the brain circulation and cause SAH, being diagnosed as idiopathic SAH or SAH with unknown cause.

Objective

The main objective of this review is to present the most relevant meteorological risk factors that may develop subarachnoid hemorrhage according to the current evidence that supports the strong association.

Conclusion

Brain vessel circulation may be influenced by atmospheric variables such as air pollution and weather changes, generating intrinsic changes in the intima of the vessels which leads to vasospasm and with comorbidities associated may develop SAH.
Myths and misperceptions in pacemaker patients: a quasi experimental study to assess effect of an educational intervention
Authors: Kubra Ghulam , Hasan Fariha , Qadir Faisal , Rasheed Shazia , Shafquat Azam
Published: July 2021

Background

Misconceptions regarding activities after pacemaker implantation can result in restrictions in daily life. This study aims at measuring the correction of misconceptions following an educational intervention utilizing a picture based brochure and personal counseling.

Methods

One hundred and twenty-eight patients were enrolled in a quasi experimental study on the day after pacemaker implantation. Patients’ perceptions about safety of various daily activities, medical procedures, and usage of appliances, in the presence of pacemaker was assessed using a questionnaire before and ten days after an educational intervention using a pictorial brochure. The number of correct responses before and after the intervention was compared to assess the change in patients’ perception.

Results

A total of 128 patients were interviewed at baseline, of which 115 followed-up at 10 days. Mean age of patients was 60.31 ± 12.81 years. In total, 76 (59.4%) were male and 61(47.7%) were illiterate. Mean correct responses increased from 64.47 ± 29.48% to 92.29 ± 14.42% (p < 0.001). Percent of questions answered correctly improved in all three categories after the intervention. Correct answers increased from 74.57 ± 24.94% to 95.65 ± 11.48% (p < 0.001) for routine daily activities, 51.09 ± 33.9% to 84.78 ± 20.86% (p < 0.001) for medical procedures and 64.03 ± 37.36% to 92.57 ± 18.79% (p < 0.001) for domestic appliance usage.

Conclusion

Misconception that can adversely affect pacemaker patient’s quality of life can be corrected by counseling with pictorial based brochures regardless of the patient’s baseline knowledge or education.
Two decades of one health surveillance of Nipah virus in Thailand
Authors: Wacharapluesadee Supaporn , Ghai Siriporn , Duengkae Prateep , Manee-Orn Pattarapol , Thanapongtharm Weerapong , Saraya Abhinbhen W. , Yingsakmongkon Sangchai , Joyjinda Yutthana , Suradhat Sanipa , Ampoot Weenassarin , Nuansrichay Bundit , Kaewpom Thongchai , Tantilertcharoen Rachod , Rodpan Apaporn , Wongsathapornchai Kachen , Ponpinit Teerada , Buathong Rome , Bunprakob Saowalak , Damrongwatanapokin Sudarat , Ruchiseesarod Chanida , Petcharat Sininat , Kalpravidh Wantanee , Olival Kevin J. , Stokes Martha M. , Hemachudha Thiravat
Published: July 2021

Background

Nipah virus (NiV) infection causes encephalitis and has > 75% mortality rate, making it a WHO priority pathogen due to its pandemic potential. There have been NiV outbreak(s) in Malaysia, India, Bangladesh, and southern Philippines. NiV naturally circulates among fruit bats of the genus Pteropus and has been detected widely across Southeast and South Asia. Both Malaysian and Bangladeshi NiV strains have been found in fruit bats in Thailand. This study summarizes 20 years of pre-emptive One Health surveillance of NiV in Thailand, including triangulated surveillance of bats, and humans and pigs in the vicinity of roosts inhabited by NiV-infected bats.

Methods

Samples were collected periodically and tested for NiV from bats, pigs and healthy human volunteers from Wat Luang village, Chonburi province, home to the biggest P. lylei roosts in Thailand, and other provinces since 2001. Archived cerebrospinal fluid specimens from encephalitis patients between 2001 and 2012 were also tested for NiV. NiV RNA was detected using nested reverse transcription polymerase chain reaction (RT-PCR). NiV antibodies were detected using enzyme-linked immunosorbent assay or multiplex microsphere immunoassay.

Results

NiV RNA (mainly Bangladesh strain) was detected every year in fruit bats by RT-PCR from 2002 to 2020. The whole genome sequence of NiV directly sequenced from bat urine in 2017 shared 99.17% identity to NiV from a Bangladeshi patient in 2004. No NiV-specific IgG antibodies or RNA have been found in healthy volunteers, encephalitis patients, or pigs to date. During the sample collection trips, 100 community members were trained on how to live safely with bats.

Conclusions

High identity shared between the NiV genome from Thai bats and the Bangladeshi patient highlights the outbreak potential of NiV in Thailand. Results from NiV cross-sectoral surveillance were conveyed to national authorities and villagers which led to preventive control measures, increased surveillance of pigs and humans in vicinity of known NiV-infected roosts, and increased vigilance and reduced risk behaviors at the community level. This proactive One Health approach to NiV surveillance is a success story; that increased collaboration between the human, animal, and wildlife sectors is imperative to staying ahead of a zoonotic disease outbreak.
The efficacy of transnasal palatal transillumination for the diagnosis of submucous cleft palate
Authors: Jamal Yasir S. , Moshref Sabah S. , Baamir Abeer M. , Kurdi Mazin O. , Jamal Doaa Y.
Published: July 2021

Background

Submucous cleft palate (SMCP) is a congenital abnormality with various clinical and anatomical features. Submucous cleft pathologies may be unrecognized during routine examinations. Current diagnostic techniques are constrained and unrevealing in presurgical patients. This prospective study aimed to evaluate transnasal palatal transillumination technique in diagnosis of SMCP at our institute hospital, during period from 2005-2020.

Patients and methods

Twenty-one cases with SMCP were recruited with age range from 2-60 months. Transnasal palatal transillumination with controllable light intensity endoscope used to evaluate SMCP and cases were photo and video recorded.

Results

In this study, 21 cases (13 males and 8 females) with SMCP were detected or confirmed by intranasal transnasal palatal transillumination. Frequency of SMCP patients at our institute was 3.39%. All patients presented with symptomatic complaints at diagnosis time, apart from 5 patients (23.8%) were diagnosed during cleft lip repair operations. Presenting symptoms were hypernasality (23.8%), delayed speech (23.8%), perforated palate with nasal escape of milk and food (14.3%), feeding difficulties (14.3%), and otitis media (4.8%). During intra-oral examination, all cases had a bifid uvula accompanied SMCP. Submucous cleft palate appeared as thin palate with central lucency. According to operative findings, operations done for repair were mostly two long palatal flaps (n = 13, 61.9%), von Langenbeck (n = 5, 23.8%), simple repair with lateral release incisions (n = 2, 9.6%), and simple repair without lateral release incision (n = 1, 4.8%).

Conclusions

Intraoperative assessment of submucous cleft palate with transnasal palatal transillumination is easy and cheap method to avoid missing cases of SMCP.
Postnatal causes and severity of persistent pulmonary Hypertension of Newborn
Authors: Arshad Muhammad Sohail , Adnan Mudasser , Anwar-ul-Haq Hafiz Muhammad , Zulqarnain Arif
Published: July 2021

Background & Objective: Persistent pulmonary hypertension of the newborn (PPHN) is described as severe respiratory failure along with hypoxaemia. PPHN is known to be linked with high morbidity and mortality around the world. This study was planned to determine the postnatal causes and assess the severity of persistent pulmonary hypertension of newborn in babies presenting to the Children’s Hospital, Multan.

Methods: This observational study was conducted at the Department of Paediatric Cardiology, The Children Hospital &Institute of Child Health, Multan, Pakistan from July to December 2019. A total of 122 confirmed cases of PPHN admitted having gestational age above 34 weeks were enrolled. Demographic data of the newborns was recorded along with maternal medical history, pregnancy status and postnatal causes of PPHN. Severity of PPHN was also recorded.

Results: Out of a total of 122 cases of PPHN, 81 (66.3%) were male. Majority, 78 (64.0%) had gestational age above 37 weeks. Mode of delivery as cesarean section was noted in 70 (57.4%). Meconium aspiration syndrome 52 (42.6%), birth asphyxia 48 (39.3%), respiratory distress syndrome 23 (18.8%) and sepsis 33 (27.0%) were found to be the commonest causes of PPHN. Severe PPHN was found to be the most frequent, noted among 63 (51.6%) while Moderate PPHN was observed in 40 (32.8%) and Mild PPHN in 19 (15.6%). Morality was noted among 26 (21.3%) of cases.

Conclusion: Meconium aspiration syndrome, birth asphyxia and respiratory distress syndrome were the commonest postnatal causes of PPHN. Severe PPHN was found to be the most frequent form of PPHN.

doi: https://doi.org/10.12669/pjms.37.5.2218

How to cite this:Arshad MS, Adnan M, Anwar-ul-Haq HM, Zulqarnain A. Postnatal causes and severity of persistent pulmonary Hypertension of Newborn. Pak J Med Sci. 2021;37(5):1387-1391. doi: https://doi.org/10.12669/pjms.37.5.2218

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.
Induced pluripotent stem cells derived cardiomyocytes from Duchenne Muscular Dystrophy patients in vitro
Authors: Ghori Fareeha Faizan , Wahid Mohsin
Published: July 2021

Objective: This study aimed at the in vitro generation of DMD-cardiomyocytes from patient-specific induced pluripotent stem cells derived from a Pakistani patient for future work on DMD in vitro disease modeling and drug testing for efficacy and toxicity.

Methods: This in vitro experimental study was carried out from December 2018 to January 2019 at Stem Cells and Regenerative Medicine Lab (SCRML) at Dow Research Institute of Biotechnology and Biomedical Sciences (DRIBBS), Dow University of Health Sciences (DUHS) Urine derived DMD-iPSCs were used which had been generated previously from a Pakistani DMD patient who had been selected through non-random purposive sampling. These were differentiated towards cardiomyocytes using Cardiomyocytes Differentiation media having specified growth factors and then the molecular characterization of the differentiated cells was done using immunofluorescence.

Results: Pakistani patient’s DMD-Cardiomyocytes were generated and their identity was confirmed by positive immunofluorescence for the expression of cardiac markers NKX2-5 and TNNT-2.

Conclusion: This study aimed for in vitro generation of DMD cardiomyocytes for future application in disease modeling, new drug testing for efficacy and toxicity, as well as for drug-testing for tailored personalized therapy. To the best of our knowledge, this was the first time DMD-Cardiomyocytes were generated from Pakistani DMD patients using their own induced pluripotent stem cells.

doi: https://doi.org/10.12669/pjms.37.5.3104

How to cite this:Ghori FF, Wahid M. Induced pluripotent stem cells derived cardiomyocytes from Duchenne Muscular Dystrophy patients in vitro. Pak J Med Sci. 2021;37(5):1376-1381. doi: https://doi.org/10.12669/pjms.37.5.3104

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.
Radiological profile of patients undergoing Chest X-ray and computed tomography scans during COVID-19 outbreak
Authors: Khan Sohail Ahmed , Manohar Murli , Khan Maria , Asad Samita , Adil Syed Omair
Published: July 2021

Background & Objective: Radiology has played a significant role in the diagnosis and quantifying the severity of COVID 19 pulmonary disease. This study was conducted to assess patterns and severity of COVID-19 pulmonary disease based on radiological imaging.

Methods: A prospective observational study was conducted in a large tertiary care public sector teaching hospital of Karachi, Pakistan from June 2020 till August 2020. All confirmed and suspected COVID-19 patients referred for chest X-rays and computed tomography (CT) scans were evaluated along with RT-PCR results. Suspected patients were followed for RT-PCR. Radiological features and severity of imaging studies were determined.

Results: Of 533 patients in whom X-rays were performed, majority had severe/critical findings, i.e., 304 (57.03%). Of 97 patients in whom CT scan was performed, mild/moderate findings were observed in 63 (64.94%) patients. Of 472 patients with abnormal X-rays, majority presented with alveolar pattern 459 (97.2%), bilateral lung involvement 453 (89.6%), and consolidation 356 (75.4%). Moreover, lobar predominance showed lower zone preponderance in 446 (94.5%) patients. Of 88 patients with abnormal CT findings, ground-glass opacity (GGO) 87 (98.9%) and crazy paving 69 (78.4%) were the most common findings. An insignificantly higher association of PCR positive cases was observed with severe/critical X-rays (p-value 0.076) and CT scan findings (p-value 0.431).

Conclusion: Most common patterns on CT scans were GGO and crazy paving. While on chest radiographs, bilateral lung involvement with alveolar pattern and consolidation were most common findings. On X-rays, majority had severe/critical whereas CT scan had mild/moderate findings.

doi: https://doi.org/10.12669/pjms.37.5.4290

How to cite this:Khan SA, Manohar M, Khan M, Asad S, Adil SO. Radiological profile of patients undergoing Chest X-ray and computed tomography scans during COVID-19 outbreak. Pak J Med Sci. 2021;37(5):1288-1294. doi: https://doi.org/10.12669/pjms.37.5.4290

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.
Ultrafast laser surgery probe with a calcium fluoride miniaturized objective for bone ablation
Authors: Subramanian Kaushik , Andrus Liam , Pawlowski Michal , Wang Ye , Tkaczyk Tomasz , Ben-Yakar Adela
Published: July 2021

We present a miniaturized ultrafast laser surgery probe with improved miniaturized optics to deliver higher peak powers and enable higher surgical speeds than previously possible. A custom-built miniaturized CaF2 objective showed no evidence of the strong multiphoton absorption observed in our previous ZnS-based probe, enabling higher laser power delivery to the tissue surface for ablation. A Kagome fiber delivered ultrashort pulses from a high repetition rate fiber laser to the objective, producing a focal beam radius of 1.96 μm and covering a 90×90 μm2 scan area. The probe delivered the maximum available fiber laser power, providing fluences >6 J/cm2 at the tissue surface at 53% transmission efficiency. We characterized the probe’s performance through a parametric ablation study on bovine cortical bone and defined optimal operating parameters for surgery using an experimental- and simulation-based approach. The entire opto-mechanical system, enclosed within a 5-mm diameter housing with a 2.6-mm diameter probe tip, achieved material removal rates >0.1 mm3/min, however removal rates were ultimately limited by the available laser power. Towards a next generation surgery probe, we simulated maximum material removal rates when using a higher power fiber laser and found that removal rates >2 mm3/min could be attained through appropriate selection of laser surgery parameters. With future development, the device presented here can serve as a precise surgical tool with clinically viable speeds for delicate applications such as spinal decompression surgeries.
Three-compartment-breast (3CB) prior-guided diffuse optical tomography based on dual-energy digital breast tomosynthesis (DBT)
Authors: Yun Sungho , Kim Yejin , Kim Hyeongseok , Lee Seoyoung , Jeong Uijin , Lee Hoyeon , Choi Young-wook , Cho Seungryong
Published: July 2021

Diffuse optical tomography (DOT) is a non-invasive functional imaging modality that uses near-infrared (NIR) light to measure the oxygenation state and the concentration of hemoglobin. By complementarily using DOT with other anatomical imaging modalities, physicians can diagnose more accurately through additional functional image information. In breast imaging, diagnosis of dense breasts is often challenging because the bulky fibrous tissues may hinder the correct tumor characterization. In this work, we proposed a three-compartment-breast (3CB) decomposition-based prior-guided optical tomography for enhancing DOT image quality. We conjectured that the 3CB prior would lead to improvement of the spatial resolution and also of the contrast of the reconstructed tumor image, particularly for the dense breasts. We conducted a Monte-Carlo simulation to acquire dual-energy X-ray projections of a realistic 3D numerical breast phantom and performed digital breast tomosynthesis (DBT) for setting up a 3CB model. The 3CB prior was then used as a structural guide in DOT image reconstruction. The proposed method resulted in the higher spatial resolution of the recovered tumor even when the tumor is surrounded by the fibroglandular tissues compared with the typical two-composition-prior method or the standard Tikhonov regularization method.
Time-domain Fabry–Perot resonators formed inside a dispersive medium
Authors: Zhang J. , Donaldson W. R. , Agrawal Govind P.
Published: July 2021

We show that the temporal analog of a Fabry–Perot resonator (FPR) can
be realized by using two moving temporal boundaries, formed by intense
pump pulses inside a dispersive medium (such as an optical fiber). We
analyze such FPRs using a transfer-matrix method, similar to that used
for spatial structures containing multiple thin films. We consider a
temporal slab formed using a single square-shape pump pulse and find
that the resonance of such an FPR has transmission peaks whose quality (

Q

) factors decrease rapidly with an
increasing velocity difference between the pump and probe pulses. We
propose an improved design by using two pump pulses. We apply our
transfer-matrix method to this design and show considerable
improvement in the

Q

factors of various peaks. We also
show that such FPRs can be realized in practice by using two short
pump pulses that propagate as solitons inside a fiber. We verified the
results of the transfer-matrix method by directly solving the pulse
propagation equation with the split-step Fourier method.
Algebraic solutions for the Fourier transform interrogator
Authors: Grillo Peternella Fellipe , Harmsma Peter , Horsten Roland C. , Zuidwijk Thim , Urbach H. Paul , Adam Aurèle J. L.
Published: July 2021

A new method for fast, high resolution interrogation of an array of photonic sensors is proposed. The technique is based on the integrated Fourier transform (FT) interrogator previously introduced by the authors. Compared to other interferometric interrogators, the FT-interrogator is very compact and has an unprecedented tolerance to variations in the nominal values of the sensors’ resonance wavelength. In this paper, the output voltages of the interrogator are written as a polynomial function of complex variables whose modulus is unitary and whose argument encodes the resonance wavelength modulation of the photonic sensors. Two different methods are proposed to solve the system of polynomial equations. In both cases, the Gröbner basis of the polynomial ideal is computed using lexicographical monomial ordering, resulting in a system of polynomials whose complex variable contributions can be decoupled. Using an NVidia graphics processing card, the processing time for 1 026 000 systems of algebraic equations takes around 9 ms, which is more than two orders of magnitude faster than the interrogation method previously introduced by the authors. Such a performance allows for real time interrogation of high-speed sensors. Multiple solutions satisfy the algebraic system of equations, but, in general, only one of the solutions gives the actual resonance wavelength modulation of the sensors. Other solutions have been used for optimization, leading to a reduction in the cross-talk among the sensors. The dynamic strain resolution is 1.66

n
ε

/

H
z

.
Investigation of corner states in second-order photonic topological insulator
Authors: Shen Shi-lei , Li Chao , Wu Jun-Fang
Published: July 2021

Recently, higher-order topological insulators have been investigated as a novel topological phase of matter that obey an extended topological bulk–boundary correspondence principle. In this paper, we study the influence of BNN interaction on photonic higher-order corner states. We find both next-nearest-neighbor (NNN) hopping and perfect electric conductor (PEC) boundaries can solely result in two kinds of corner states which are quite different from the traditional “zero-energy” state. To demonstrate this intuitively, we design a novel all-dielectric structure that can effectively shield the influence of NNN couplings while remain the effect of PEC boundaries, so that we can distinguish the contributions from NNN hopping and PEC boundaries. In addition, we also investigate the total contribution on corner states when NNN couplings and PEC boundaries coexist, and some interesting features are revealed. These findings may expand our understanding of the high-order corner modes in a more general framework.
SOA pattern effect mitigation by neural network based pre-equalizer for 50G PON
Authors: Xue Lei , Yi Lilin , Lin Rui , Huang Luyao , Chen Jiajia
Published: July 2021

Semiconductor optical amplifier (SOA) is widely used for power amplification in O-band, particularly for passive optical networks (PONs) which can greatly benefit its advantages of simple structure, low power consumption and integrability with photonics circuits. However, the annoying nonlinear pattern effect degrades system performance when the SOA is needed as a pre-amplifier in PONs. Conventional solutions for pattern effect mitigation are either based on optical filtering or gain clamping. They are not simple or sufficiently flexible for practical deployment. Neural network (NN) has been demonstrated for impairment compensation in optical communications thanks to its powerful nonlinear fitting ability. In this paper, for the first time, NN-based equalizer is proposed to mitigate the SOA pattern effect for 50G PON with intensity modulation and direct detection. The experimental results confirm that the NN-based equalizer can effectively mitigate the SOA nonlinear pattern effect and significantly improve the dynamic range of receiver, achieving 29-dB power budget with the FEC limit at 1e-2. Moreover, the well-trained NN model in the receiver side can be directly placed at the transmitter in the optical line terminal to pre-equalize the signal for transmission so as to simplify digital signal processing in the optical network unit.
Vibrant reflective sensors with percolation film Fabry-Pérot nanocavities
Authors: Palinski Timothy J. , Tadimety Amogha , Trase Ian , Vyhnalek Brian E. , Hunter Gary W. , Garmire Elsa , Zhang John X. J.
Published: July 2021

Dynamically reconfigurable structural colors are promising materials for new smart optical systems. However, improved reflected color quality (e.g., saturation, optical contrast, angular invariance) and larger tuning range/sensitivity are needed. Here, we demonstrate a vibrant, actively tunable system which meets these needs via coupling broadband plasmonic resonators to a responsive polymer film. Our structure consists of near-percolation gold nanoislands deposited on a poly[methyl methacrylate] (PMMA) spacer above a gold mirror, forming a Fabry–Pérot nanocavity. Broadband absorption in this system creates vivid reflected colors, while the polymer spacer enables continuous tuning over a wide color space. By exploiting swelling effects in PMMA, we show fast, reversible color switching in response to organic vapors. Our sensitive optical structure amplifies small vapor-induced changes in the spacer thickness, enabling naked-eye detection of changes as small as 10 nm. Additionally, optical absorption >99% yields modulation contrasts up to 80:1, opening the door to ultra-sensitive on-chip signal measurements, complementing the visual colorimetric readout. This structure has immediate implications for colorimetric bio/chemical sensing and may also find application to reflective displays and flexible/adaptive optical coatings.
Full color single pixel imaging by using multiple input single output technology
Authors: Wang Le , Zhao Shengmei
Published: July 2021

In this paper, we propose a novel full color single pixel imaging by using multiple input single output (MISO) technology. In the scheme, the MISO technology, which is widely used in the wireless communications, is used to simultaneously produce three (red, green and blue) detection signal components corresponding to the red, green and blue components of the object with only one single pixel bucket detector respectively. Then, a full color image of object can be produced by synthesizing the reconstructed red, green and blue component images of object, where the red (green or blue) component image can be recovered by utilizing the speckle patterns and corresponding detection signal components. The experimental results demonstrate that our scheme can be robust against the interference of the intensity fluctuations of ambient light and improve the imaging quality. Moreover, our scheme requires only one single pixel bucket detector, which reduces the numbers of bucket detectors that need to be used. Our scheme provides a promising avenue to realize the full color single pixel imaging with MISO technology and has the potential to be extended to high quality multispectral single pixel imaging by using only one single pixel detector.
Global optimization for light concentrators of a Geiger-mode cosmic-ray Cherenkov calorimeter
Authors: Chong Wang , Wei Zhang , Xing Zhang J. , Jin Ba
Published: July 2021

Light concentrators are crucial devices for photon-counting instruments, the optical characteristics of which affect the photoelectric response for the sensors. The designs that only aim to the light transmission have been proved far from optimum for the Geiger-mode calorimeters due to the significant influence from the angle-dependent reflectance, versatile light trajectories, and saturation of fired avalanche photodiodes (APDs). In this paper, we took into account these coupling effects, presented a novel approach to solve the problems in global optimization for light concentrators in combination with silicon photomultiplier (SiPM). In addition, a new probability method is studied and used to restore the photon counting for precise reconstruction of cosmic-ray air showers. The Monte-Carlo experiment verified that the new system design features a high accurate energy scaling for cosmic-ray measurement. The results also indicate that the precision is able to be improved by at least one order in magnitude.
Versatile butt-joint regrowth for dense photonic integration
Authors: Wang Yi , van Engelen Jorn , van Veldhoven Rene , de Vries Tjibbe , Dolores-Cazadilla Victor , Smit Meint , Williams Kevin , Jiao Yuqing
Published: July 2021

Butt-joint regrowth is widely used in photonic integration, but it has been challenging to break the density-quality tradeoff due to the edge growth rate enhancement (GRE) effect. In this work, we propose a scheme to circumvent this tradeoff by using large regrowth masks whose centers are exposed to epi-growth for neutralization of the excessive species. With the GRE under control, epi-stacks with arbitrarily large sizes supporting dense arrays can be butt-joint integrated with minimal compromise to their epitaxy quality. In our experiment, multi-quantum-well-based material of an exceptionally large area of 0.5 × 1.7 mm2 was epitaxially integrated with passive InP material on the same wafer. A more than 20 × reduction in edge topology compared to conventional methods was achieved.
Visible to near-infrared broadband fluorescence from Ce-doped silica fiber
Authors: Yadav Amit , Chichkov Nikolai B. , Gumenyuk Regina , Ali-Löytty Harri , Lahtonen Kimmo , Valden Mika , Melkumov Mikhail A. , Yashkov Mikhail V. , Zherebtsov Evgeny , Rafailov Edik U.
Published: July 2021

We investigate the fluorescence characteristics of a purely Ce-doped silica fiber and demonstrate broad-bandwidth fluorescence across the visible and near-infrared. The Ce-doped fiber is fabricated using standard modified chemical vapor deposition technology. Trace metal analysis by inductively coupled plasma mass spectrometry confirmed the purity of Ce-doping. The Ce valence state of 3+ was revealed by X-ray photoelectron spectroscopy. The optimum pump wavelength for the broadest luminescence from a fiber is scanned between 405 nm to 440 nm wavelength of diode lasers operating under continuous-wave regime. The strongest pump absorption is observed at the wavelength of 405 nm. Variation of pump power and fiber length results in the demonstration of broad-bandwidth fluorescence with spectral widths up to 301 nm (at -10 dB). The measured fluorescence spectra cover the wavelength range from ∼458 nm to ∼819 nm with spectral power densities of up to 2.4 nW/nm.
Optimized two-layer motheye structures for MgAl2O4 spinel ceramic windows
Authors: Tu Chaoran , Hu Jonathan , Menyuk Curtis R. , Carruthers Thomas F. , Brandon Shaw L. , Busse Lynda E. , Sanghera Jasbinder S.
Published: July 2021

We computationally study two-layer motheye nanostructures fabricated on MgAl2O4 spinel ceramic windows. We investigated the parameters of the structure, including height, width, and shape, in order to optimize its power transmission efficiency over a broad bandwidth. We found a two-layer motheye structure in which the cones of the upper structure have a concave shape that can theoretically achieve more than 99.8% transmission at normal incidence in the wavelength range between 0.4 μm and 5.0 μm.
Multi-parabolic illuminator to combine perpendicular collimated illuminations with an LED source
Authors: Ohno Hiroshi
Published: July 2021

Collimated illumination with a light-emitting diode (LED) is widely used in the residential, commercial, and industrial inspection fields. A slim LED illuminator composed of multi-parabolic surfaces to combine perpendicular collimated illuminations is proposed here. The multi-parabolic illuminator can produce a collimated rectangular illumination where light angle distributions for perpendicular axes can independently be controlled by different parabolic surfaces. This independence of the control makes the design of the illuminator simple. A prototype of the multi-parabolic illuminator is fabricated with an LED chip size of 3×3 mm and an opening aperture size of 20×60 mm. A maximum width of the prototype is 20 mm. The prototype demonstrates a production of a highly collimated rectangular illumination with half-intensity angles of about 7 degrees and 34 degrees for respective perpendicular axes.
Early Evidence of Producing Economy in the Hissar Culture: An Overview of Research Concepts
Authors:   Institute of Archaeology and Ethnography, Siberian Branch of the Russian Academy of Sciences, G. Markovsky , S. Alisher kyzy ,   Institute of Archaeology and Ethnography, Siberian Branch of the Russian Academy of Sciences,   Novosibirsk State University, S. Shnaider ,   Institute of Archaeology and Ethnography, Siberian Branch of the Russian Academy of Sciences
Published: July 2021

The transition to farming is a revolutionary step in human history. Domesticated species of cereals and small ruminants which spread from the territory of the countries of the Fertile Crescent appear in Central Asia during the early Neolithic period (the 6th — 5th millennium BC). In the middle of the 20th century several Neolithic cultures prominent for the Central-Asian region were defined: Jeitun, Kelteminar and Hissar. This publication is devoted to the consideration of the Hissar culture and the existing reconstructions of its economic structure. The Gissar culture is widespread on the territory of the Gissar-Alai and dates from the 6th to the 2nd millennium BC. Since the late 1950s the researchers tried to determine the type of economy of the carriers of the Hissar culture: the early stage of agriculture and cattle breeding; hunting and gathering; nomadic cattle breeding. This article examines the main arguments “for” and “against” the existence of a productive economy in the Hissar culture, namely, cattle breeding. Based on a number of signs, such as the presence of long-term and short-term camps, a large number of bones of small ruminants, the availability of year-round pastures at the site, the absence of hunting tools in the toolkit, the team of authors agrees with the point of view of V. A. Ranova and G. F. Korobkova about the use of early cattle breeding by the Hissar people. However, this hypothesis requires additional elaboration using bioarchaeological research methods. Keywords: Central Asia, Hissaro-Alay, Hissar, Neolithic, pastopalism Acknowledgements: The analysis of the general problems was carried out with the support of the project of the Russian Science Foundation No. 19–78–10053 “Origin of the Industrial Economy in the Mountainous Part of Central Asia”, the analysis of materials from the Hissar culture was carried out within the framework of the research program No. 0329–2019–0002 “Ancient Cultural Processes in the Territory of Central Asia”.
Rare Metal Mirror of the Jurchen Time From Tuva
Authors:   Altai State University, N. Seregin , A. Chistyakova ,   Novosibirsk State Pedagogical University, K. Mongush ,   National Museum of Tyva Republic named after Aldan-Maadyr
Published: July 2021

Abstract: The article presents the publication and diverse interpretation of a fragment of a rare metal mirror from the collection of the National Museum of the Republic of Tyva (Kyzyl city). The attribution of the composition, placed in the preserved part of the ornamental field of the mirror, required an appeal to the extensive collections of Chinese objects reflected in catalogs and special literature. It is established that the product belongs to a rare group of finds depicting the scene of the conversation “Xu Yu and Chao Fu” — a plot known since the Han Dynasty. An examination of the features of casting, the design of the rim, and the stylistics of the images of the published mirror shows that the manufacture of this item can be attributed to the period of the non-Chinese Jin Dynasty (1115–1234 AD). The significance of the fragment in the system of similar objects found on the territory of Tuva was determined by a review of known finds. The published fragment, the production of which dates back to the Jurchen time, demonstrates the latest period in the distribution of such objects in Tuva. It is important that the product shows a very rare specimen of a mirror, full analogies of which are absent not only in the designated region, but also, as far as we know, have not yet been identified in the sites of North and Central Asia. Keywords: metal mirror, Tuva, museum collections, China, Jurchen time, interpretation Acknowledgements: The study was carried out with the financial support of the Russian Foundation for Basic Research and the Ministry of Culture, Education, Science and Sports of Mongolia within the framework of the scientific project No. 19–59–44013 “Historical, Сultural and Ehnogenetic Processes in Mongolia during the Great Migration and the Early Middle Ages: an Interdisciplinary Analysis of Archaeological and Written Sources”.
Archaeological Jubilrr on the Occasion of the Centenary of Birth of Betty Meggers (1921–2012)
Authors:   Institute of Archaeology and Ethnography SB RAS, T. Gavrilina , A. Tabarev ,   Institute of Archaeology and Ethnography SB RAS
Published: July 2021

This article is related to the 100th anniversary of the birth of the world famous North American archaeologist Betty Jane Meggers (1921–2012), who made an invaluable contribution to the study of archaeological antiquities in Ecuador, Brazil, Venezuela, Chile, Peru, etc. Her long list of achievements includes the creation of a chronological chart for the archaeological cultures of the coastal part of Ecuador (in collaboration with Clifford Evans), remaining relevant today. Also, the name of B. J. Meggers is often mentioned in the context of the debatable hypothesis “Jōmon-Valdivia” which was made at the very beginning of the 1960s. It is focused on the possibility of transoceanic contacts between the population of the Japanese archipelago and the inhabitants of the Pacific coast of South America 5500–6000 years ago. This was preceded by a significant period of B. Meggers’ work in the Amazon (1947–1954). A brief outline of the first half of life and career of the North American researcher allows us to trace the main stages of transformations of her scientific interests. Keywords: South America, Brazil, Ecuador, Amazonia, biography, research history