bluuebunny/crossref_metadata_2025 huggingface dataset:
Dapagliflozin Improves Body Fat Patterning, and Hepatic and Pancreatic Fat in Patients With Type 2 Diabetes in North India
Authors: Ghosh Amerta , Dutta Koel , Bhatt Surya Prakash , Gupta Ritesh , Tyagi Kanika , Ansari Irshad Ahmad , Venugopal Vasantha Kumar , Mahajan Harsh , Pandey Ravindra Mohan , Pandey Shivam , Misra Anoop
Published: March 2022

Context

Excess hepatic and pancreatic fat may contribute to hyperglycemia.

Objective

The objective of this study was to examine the effect of dapagliflozin (an SGLT2 inhibitor) on anthropometric profile, liver, and pancreatic fat in patients with type 2 diabetes mellitus (T2DM).

Methods

This is an observational interventional paired study design without a control group. Patients (n = 30) were given dapagliflozin 10 mg/day (on top of stable dose of metformin and/or sulfonylureas) for 120 days. Changes in anthropometry (circumferences and skinfold thickness), surrogate markers of insulin resistance, body composition, liver, and pancreatic fat (as measured by magnetic resonance imaging (MRI)-derived proton density fat fraction [FF]) were evaluated.

Results

After 120 days of treatment with dapagliflozin, a statistically significant reduction in weight, body mass index (BMI), body fat, circumferences, and all skinfold thickness was seen. A statistically significant reduction in blood glucose, glycated hemoglobin A1c, hepatic transaminases, fasting insulin, homeostatic model assessment of insulin resistance (HOMA-IR), and postprandial C-peptide was noted, while HOMA-β, postprandial insulin sensitivity, and fasting adiponectin were statistically significantly increased. There was no change in lean body mass. Compared to baseline there was a statistically significant decrease in mean liver FF (from 15.2% to 10.1%, P < .0001) and mean pancreatic FF (from 7.5% to 5.99%, P < .0083). Reduction in liver fat was statistically significant after adjustment for change in body weight.

Conclusion

Dapagliflozin, after 120 days of use, reduced pancreatic and liver fat and increased insulin sensitivity in Asian Indian patients with T2DM.
Life After Loss: A Prospective Analysis of Mortality Exposure and Unintended Fertility
Authors: Smith-Greenaway Emily , Yeatman Sara , Chilungo Abdallah
Published: March 2022

The relationship between mortality and fertility is a key component of demographic transition theory, placing it at the center of extensive inquiry. Among other linkages, mortality in women's communities and social networks influences their subsequent fertility. Existing demographic research assumes this is principally due to volitional mechanisms, implying that exposure to mortality consolidates women's desire to become pregnant, leading to intended fertility. Yet, insights from other disciplines suggest that mortality exposure could also increase women's unintended fertility through psychological, relational, and behavioral mechanisms. This study examines the relationships between network mortality exposure and women's hazard of pregnancy, and of unintended pregnancy specifically. We analyze two years (2009–2011) of closely spaced panel data on young Malawian women (N=1,272) enrolled in the Tsogolo la Thanzi study. Our data include information on funeral attendance and fertility desires measured weeks before conception, which is confirmed through frequent pregnancy testing. Hazard models show that the number of funerals women attend corresponds with a higher hazard of pregnancy and of unintended pregnancy specifically. These findings make clear that mortality exposure can influence fertility not by shaping women's desires but by disrupting the realization of those desires.
Risk Stratification to Define the Role of Radiotherapy for Benign and Atypical Meningioma: A Recursive Partitioning Analysis
Authors: Chang Won Ick , Kim Il-Han , Choi Seung Hong , Kim Tae Min , Lee Soon-Tae , Won Jae Kyung , Park Sung-Hye , Kim Min-Sung , Kim Jin Wook , Kim Yong Hwy , Park Chul-Kee , Lee Joo Ho
Published: March 2022

BACKGROUND:

The role of adjuvant radiotherapy (RT) for benign or atypical meningioma is controversial.

OBJECTIVE:

To identify prognostic factors and a subgroup that could be potentially indicated for adjuvant RT.

METHODS:

A total of 336 patients with benign and 157 patients with atypical meningioma underwent surgical resection between January 2015 and December 2019. We retrospectively analyzed 407 patients who did not receive adjuvant RT to stratify risk groups for recurrence. A recursive partitioning analysis (RPA) with the prognostic factors for their failure-free survival (FFS) divided the patients into risk groups.

RESULTS:

The 3-year FFS with surgical resection only was 76.5%. Identified prognostic factors for FFS were skull base location, tumor size, brain invasion, a Ki-67 proliferation index of ≥5%, and subtotal resection. The RPA-classified patients were divided into 4 risk groups: very low, low, intermediate, and high, and their 3-year FFS were 98.9%, 78.5%, 59.8%, and 34.2%, respectively. Intermediate-risk and high-risk groups comprise the patients with meningioma of sizes ≥2 cm after subtotal resection or meningioma of sizes >3 cm, located in the skull base or with brain invasion, respectively. After combining with patients treated with adjuvant RT, no FFS benefit was found in the very low-risk and low-risk groups after adjuvant RT, whereas significantly improved FFS was found in the intermediate-risk and high-risk groups (P < .05).

CONCLUSION:

The RPA classification revealed a subgroup of patients who could be potentially indicated for adjuvant RT even after gross total resection or for whom adjuvant RT could be deferred.
Effect of acarbose combined with diet intervention on glycolipid metabolism in patients with primary polycystic ovarian syndrome complicated with impaired glucose tolerance
Authors: Yang Qian  , Zhang Wenjuan , Zhang Junfei , Niu Shuai
Published: March 2022

Objectives: To investigate the efficacy of acarbose combined with diet intervention in patients with primary polycystic ovarian syndrome (PCOS) complicated with impaired glucose tolerance (IGT) and its effect on their glycolipid metabolism.

Methods: A total of 92 patients with primary PCOS complicated with IGT treated in our hospital from December 2018 to December 2020 were selected, and divided into two groups using a random number table. The control group received routine lifestyle intervention. On this basis, the observation group was treated with acarbose combined with diet intervention. The menstrual recovery rate, ovulation rate and pregnancy rate after treatment, as well as sex hormone levels, glycolipid metabolism and inflammatory factor levels before and after treatment were compared between the two groups.

Results: After treatment, the menstrual recovery rate and ovulation rate of the observation group were significantly higher than those of the control group (P < 0.05). Among the patients with fertility needs in the two groups, the pregnancy rate of the observation group was significantly higher compared with the control group (P < 0.05). Before treatment, sex hormone levels showed no obvious differences between the two groups (P > 0.05). After treatment, all indicators of sex hormone were improved in both groups, and the improvement in the observation group was more obvious than that in the control group (P < 0.05). Before treatment, no obvious difference was found in glycolipid metabolism between the two groups (P > 0.05). After treatment, 2hPG, LDL-C and TG were improved in both groups, and the improvement was more significant in the observation group compared with the control group (P < 0.05). Before treatment, inflammatory factor levels were not significantly different between the two groups (P > 0.05). After treatment, inflammatory factor levels in both groups were improved, which was more obvious in the observation group than the control group (P < 0.05).

Conclusions: The application of acarbose combined with diet intervention in patients with primary PCOS complicated with IGT can effectively enhance the efficacy, help patients increase ovulation rate and pregnancy rate, and improve sex hormone levels, glycolipid metabolism and inflammatory factor levels.

doi: https://doi.org/10.12669/pjms.38.4.4598

How to cite this:Riaz A, Sughra U, Jawaid SA, Masood J. Measurement of Service Quality Gaps in Dental Services using SERVQUAL in Public Hospitals of Rawalpindi. Pak J Med Sci. 2022;38(4):---------. doi: https://doi.org/10.12669/pjms.38.4.4598

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.
Time for culture conversion and its associated factors in multidrug-resistant tuberculosis patients at a tertiary level hospital in Peshawar, Pakistan
Authors: Iqbal Zafar , Ali Khan Mazhar , Aziz Aamir , Nasir Syed Muhammad
Published: March 2022

Objectives: This study aimed to assess the time to sputum culture conversion (SCC) and its determinants among multidrug-resistant tuberculosis (MDR-TB) patients.

Methods: This cross-sectional study was conducted from January 2019 to January 2020. A total of 252 MDR-TB patients presenting at a tertiary level teaching hospital in Peshawar, Khyber Pakhtunkhwa (KP), were included. The patient’s demographic and clinical data were collected using a structured questionnaire. Time to SCC was calculated from the initiation of treatment till the patient had two consecutive negative cultures. The Cox proportional-hazards analysis was performed to check strength and association between the determinants and time for SCC.

Results: Out of 252 MDR-TB patients enrolled, sputum culture conversion was observed in 76.6% of the patients by the end of six months. While, 19.0% of the patients failed to achieve negative culture and remained positive after interim report of their treatment. Age > 45 years (HR = 15.22; 95% CI: 7.27-31.83; p<0.001), female gender (6.22; 2.90-13.36; p<0.001), BMI < 18.5 kg/m2 (10.28; 5.25-20.11; p<0.001), weight loss (0.03; 0.01-0.06; p<0.001), smoking (0.10; 0.05-0.21; p<0.001), diabetes mellitus (0.02; 0.00-0.04 p<0.001) and disease severity on chest X-ray (CXR) (0.03; 0.01-0.09; p<0.001) were the significant determinants of delayed sputum culture conversion.

Conclusion: MDR-TB patients with older age, low BMI, weight loss, diabetes, smokers and those with disease severity on CXR are less likely to respond to treatment as they displayed delayed SCC. Therefore, such patients should be meticulously followed up for successful management.

doi: https://doi.org/10.12669/pjms.38.4.5058

How to cite this:Iqbal Z, Khan MA, Aziz A, Nasir SM. Time for culture conversion and its associated factors in multidrug-resistant tuberculosis patients at a tertiary level hospital in Peshawar, Pakistan. Pak J Med Sci. 2022;38(4):---------. doi: https://doi.org/10.12669/pjms.38.4.5058

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.
The comparison of clinical effect, knee function, prognosis of double plate fixation and locking plate internal fixation for tibial plateau fractures
Authors: Zhang Qing , Zhao Jianzhong , Zhang Guangcheng , Tang Jiazhu , Zhu Wei , Nie Mingjun
Published: March 2022

Objectives: The purpose of this study was to investigate the clinical effect, knee function improvement and prognosis of double plate internal fixation and locking plate internal fixation in the treatment of tibial plateau fractures.

Methods: Clinical data from 96 tibial plateau fracture patients treated at our hospital were analyzed retrospectively. Of these, 46 had been treated using locking plate internal fixation and 50 were treated with double T-shaped plate fixation. Clinically related indices, Hospital for Special Surgery (HSS) score of knee function, and ability of daily living (ADL) score were evaluated during postoperative follow-up.

Results: No significant differences were observed in pre-operative patient characteristics in both groups. Healing time, time to weight-bearing, tibial plateau angle (TPA) and lateral posterior angle (PA) were all superior in the locking plate fixation group compared to the double plate fixation group. At three months post-operative visit, range of motion, knee function, flexion deformity, muscle strength, pain, and stability metrics were all superior in the locking plate fixation group compared to the double plate fixation group. ADL scores were also higher in the locking plate fixation group than in the double plate fixation group at three and six months follow-up.

Conclusions: The clinical effect, knee function improvement and prognosis of locking plate internal fixation in the treatment of tibial plateau fractures are better than those of double plate fixation.

doi: https://doi.org/10.12669/pjms.38.4.5340

How to cite this:Zhang Q, Zhao J, Zhang G, Tang J, Zhu W, Nie M. The comparison of clinical effect, knee function, prognosis of double plate fixation and locking plate internal fixation for tibial plateau fractures. Pak J Med Sci. 2022;38(4):---------.  doi: https://doi.org/10.12669/pjms.38.4.5340

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.
Application and clinical significance of tissue ultrasound for assessment of right ventricular diastolic function in patients with coronary slow flow
Authors: Zhu Xuefang , Xu Xiuping , Wei Zhen , Zhu Zenghua
Published: March 2022

Objectives: To evaluate right ventricular diastolic function in patients with coronary slow flow phenomenon (CSFP) by using Doppler tissue imaging (DTI).

Methods: CSFP patients diagnosed using coronary angiography from June 2019 to December 2020 at the third Hospital of Quzhou were retrospectively investigated, with a similar number of patients with normal coronary blood flow during the same period taken as the control group. Right ventricular systolic and diastolic function index was measured via DTI.

Results: No differences were found between CSFP and control groups in terms of baseline data, RV end systolic diameter, RV end diastolic diameter, or RV ejection fraction. The peak velocity E in the early diastolic phase of the right ventricle was decreased in CSFP patients, while the peak velocity a in the late diastolic phase of the right ventricle was increased, resulting in a lower E / a ratio.

Conclusions: Right ventricular diastolic function in patients with CSFP is decreased, and this can be identified using DTI. DTI has important applicative value for evaluating right ventricular diastolic function in patients with CSFP.

doi: https://doi.org/10.12669/pjms.38.4.5342

How to cite this:Zhu X, Xu X, Wei Z, Zhu Z. Application and clinical significance of tissue ultrasound for assessment of right ventricular diastolic function in patients with coronary slow flow. Pak J Med Sci. 2022;38(4):---------.  doi: https://doi.org/10.12669/pjms.38.4.5342

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.
Promising sequels of a novel nanoformulation of khamira abresham hakim Arshadwala against isoprenaline challenged cardiac damage in rodents
Authors: Mahmood Tarique , Shamim Arshiya , Shariq Mohammad , Siddiqui Mohammed Haris , Ahsan Farogh , Parveen Saba
Published: March 2022

Background: Khamira Abresham Hakim Arshadwala (KAHAW), a distinguished, traditional Unani formulation comprising constituents of herbal, animal, and mineral origin, holds salubrious cardioprotective potential and has been used for cardiac ailments in the Unani system for ages. KAHAW is a ‘sugar-based’ preparation, which hinders its ‘claim to fame’ amongst cardiac patients with diabetes. Hence, it is fascinating to develop a novel nanoformulation of the traditional one and screen its efficacy experimentally on the male Wistar rats (4-week-old) (150-180gm). The objective was to revolutionize this historic gem of a formulation and enhance its therapeutic efficacy, a novel nanoformulation of KAHAW was developed, and its cardioprotective potential screened against isoprenaline (ISO) induced cardiotoxicity in rodents. The results were analyzed with the traditional formulations and two clinically used drugs, Ramipril and Carvedilol.

Methods: Various parameters viz; Physical, Enzymatic, Non-enzymatic, and cardiac-specific biomarkers like α/β-MHC expression (Western Blot), Flow cytometry, Cardiac collagen content, and Mitochondrial enzyme assay were assessed on plasma, blood, and tissue samples followed by histomorphological investigations.

Results: The effect of nanoformulation showed highly significant results (***p<0.001) when compared to disease control for different parameters viz, Total protein, GPx and GSH, Lipid peroxidation, and Vitamin E. The cardiac-specific biomarkers like α/β-MHC Expression (Western Blot), Flow Cytometry, Cardiac collagen content, and Mitochondrial enzyme assay also advocated the highly significant (***p<0.001) cardioprotective activity of the developed nanoformulation.

Conclusions: The research reiterates that the novel nanoformulation offers improved efficacy at a reduced dose against ISO-induced experimental models of myocardial necrosis.
Current management of adults receiving oral anti-cancer medications: A scoping review protocol
Authors: Richmond Janice P. , Kelly Mary Grace , Johnston Alison , Hynes Lisa , Murphy Patrick J. , Murphy Andrew W.
Published: March 2022

Oncology has been undergoing a profound transition in the last ten years with the increased usage in oral anti-cancer medication. Approximately 25% of all anti-cancer medication is now designed for oral use and this is likely to increase prospectively. These treatments are convenient for patients and are often preferred by them, yet there are similar safety and toxicity concerns as there are to intravenous treatment. Oral anti-cancer medications (OAMs) have the potential to alleviate capacity issues in cancer treating units as patients receive their treatment at home, however there remains a requirement for safe and efficient assessment and care. Consequently, the management of patients on OAMs is of paramount importance. The optimum setting, whether within primary or secondary care, in addition to the appropriate health care professional to carry out patient assessment and monitoring needs to be established.

This paper presents a protocol for a scoping review which aims to systematically and comprehensively map the literature on the current management of adults receiving OAMs. The review will follow the published guidance to direct the various steps involved. The protocol will be guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews (PRISMA-ScR) framework to ensure methodological and reporting quality. Independent full text review will be performed by two reviewers and any disagreements resolved through discussion with a third reviewer. The process will be iterative in nature.

This scoping review will provide a narrative synthesis and map the literature on the management of individuals receiving OAMs. This work is an appropriate initial stage in presenting the literature to inform the subsequent steps in a multi-phased research study which aims to establish and analyse the safety and efficacy of an integrated care model for the management of patients receiving OAM in the community by an advanced practitioner.
Developing consensus-based recommendations for the delivery of dementia services for the LGBTQIA+ community in the Republic of Ireland
Authors: Oglesby Megan H. , Hynes Sinéad M.
Published: March 2022

Background: The number of older LGBTQIA+ adults is set to rise significantly in the coming years. The rising numbers sit together with the rise in the number of people in Ireland diagnosed with dementia. In Ireland, no dementia-specific services exist for people from the LGBTQIA+ community. The aim of this research was to 1) identify the future needs that older LGTBQIA+ people and their care partners living in Ireland have in relation to dementia care service delivery; and to 2) develop consensus-based recommendations for dementia service provision in Ireland.

Methods: A six-phase consensus process was used to develop the lists of needs and recommendations: 1) development; 2) national survey; 3) interviews with key stakeholders; 4) international review of best practice; 5) consensus meeting; 6) final member checking. Participants, aged over 50, were based in Ireland, identified as a member of the LGBTQIA+ community or supported someone who is/was.

Results: Results are reported from the survey (n=49), individual interviews (n=8), and the consensus meeting (n=10). Participants have concerns related to identity management and suppression, creating an LGBTQIA+ affirmative ethos and workforce, and respect and safety. From the results and consensus process, a full list of ten prioritised needs and recommendations have been developed that focus specifically on dementia care in Ireland for the LGBTQIA+ community.

Conclusion: The older LGBTQIA+ community has identified essential priorities for improving healthcare access and safety. These priorities now need to be urgently implemented into clinical and dementia care services.
From P4 medicine to P5 medicine: transitional times for a more human-centric approach to AI-based tools for hospitals of tomorrow
Authors: Amram Denise , Cignoni Arianna , Banfi Tommaso , Ciuti Gastone
Published: March 2022

Within the debate on shaping future clinical services, where different robotics and artificial intelligence (AI) based technologies are integrated to perform tasks, the authors take the chance to provide an interdisciplinary analysis required to validate a tool aiming at supporting the melanoma cancer diagnosis. In particular, they focus on the ethical-legal and technical requirements needed to address the Assessment List on Trustworthy AI (ALTAI), highlighting some pros and cons of the adopted self-assessment checklist. The dialogue stimulates additionally remarks on the EU regulatory initiatives on AI in the healthcare systems.
Erratum: “Transform Methods for Heavy-Traffic Analysis”
Authors: Hurtado-Lange Daniela , Maguluri Siva Theja
Published: March 2022

In Hurtado-Lange and Maguluri (2020) [Transform methods for heavy-traffic analysis. Stochastic Systems 10(4):275–309], the statement of Claim 4 has a typo; it should say that the expression therein is bounded by a constant. The statement of Lemma 11, and Lemma 14 is incorrect. The lemmas should show the existence of the moment generating function in an interval around the origin with the length being independent of the heavy-traffic parameter. The correct statements and proofs are provided.
Mandatory vaccination for healthcare workers: an ethical dilemma?
Authors: Tang Sammer , Stanley Jake , Campbell Iain
Published: March 2022

Vaccines are advocated as the best defence against COVID-19. While most NHS staff, including ambulance clinicians, have been vaccinated, some remain hesitant. All health and social care staff, with some exemptions, were originally expected to be fully vaccinated by 1 April 2022. However, this is currently on hold due to the recent reconsideration by the Secretary of State. There are ethical arguments against and in favour of mandatory vaccination. Arguments against include potential harm and loss of autonomy. Coercing staff may be interpreted by the public that health professionals do not trust vaccines. A mandate may also be seen as authoritarian, which may embolden the anti-vaccine movement. Compulsory vaccination is also opposed by Royal Colleges, professional bodies and trade unions. Arguments to support mandatory vaccination include that society has a legitimate interest in regulating behaviour that harms others, even if this limits individual choices and that people live in groups so their rights and powers are limited by the rights of others. Paramedics deal with a diverse population, and often encounter clinically vulnerable patients as well as those who are COVID-19 positive. It can be argued that patients' right to be safe from unnecessary risk usurps that of a practitioner to refuse vaccination. Having all health and social care staff fully vaccinated will increase the health service's resilience. Future decisions on any vaccine mandates must incorporate various ethical arguments and support with additional effort to address underlying issues related to vaccine hesitancy.
Effect of the additional anteroposterior blocking screw on nail/medullary canal mismatch after cephalomedullary nailing in unstable pertrochanteric fracture
Authors: Kwak Dae-Kyung , Oh Seog-Hyun , Lee Sung-Jae , Lee Seung-Hun , Lee Yong-Min , Yoo Je-Hyun
Published: March 2022

Aims

There are concerns regarding nail/medullary canal mismatch and initial stability after cephalomedullary nailing in unstable pertrochanteric fractures. This study aimed to investigate the effect of an additional anteroposterior blocking screw on fixation stability in unstable pertrochanteric fracture models with a nail/medullary canal mismatch after short cephalomedullary nail (CMN) fixation.

Methods

Eight finite element models (FEMs), comprising four different femoral diameters, with and without blocking screws, were constructed, and unstable intertrochanteric fractures fixed with short CMNs were reproduced in all FEMs. Micromotions of distal shaft fragment related to proximal fragment, and stress concentrations at the nail construct were measured.

Results

Micromotions in FEMs without a blocking screw significantly increased as nail/medullary canal mismatch increased, but were similar between FEMs with a blocking screw regardless of mismatch. Stress concentration at the nail construct was observed at the junction of the nail body and lag screw in all FEMs, and increased as nail/medullary canal mismatch increased, regardless of blocking screws. Mean stresses over regions of interest in FEMs with a blocking screw were much lower than regions of interest in those without. Mean stresses in FEMs with a blocking screw were lower than the yield strength, yet mean stresses in FEMs without blocking screws having 8 mm and 10 mm mismatch exceeded the yield strength. All mean stresses at distal locking screws were less than the yield strength.

Conclusion

Using an additional anteroposterior blocking screw may be a simple and effective method to enhance fixation stability in unstable pertrochanteric fractures with a large nail/medullary canal mismatch due to osteoporosis. Cite this article: Bone Joint Res 2022;11(3):152–161.
Lateral waveguide scanner integration on surface-emitting mid-infrared lasers
Authors: Yao Danyang , Zhang Jinchuan , Jia Zhiwei , Liu Yan , Liu Shuman , Han Genquan , Liu Fengqi , Hao Yue
Published: March 2022

In this paper, a novel, to the best of our knowledge, monolithic non-mechanical semiconductor laser scanner in the mid-infrared (MIR) spectrum is proposed. A deflector above the active region at the substrate side is used for coupling the vertical light into a lateral substrate waveguide, which creates a chain of coherent emitters such as optical phased arrays (OPAs) for beam steering. The numerical simulation reveals that GaSb-based surface-emitting interband cascade lasers (SE-ICLs) are an excellent platform for waveguide scanner integration. Due to the hundreds of micrometers of optical path difference and the narrow gap between each emitter, an extremely high angle tuning coefficient of 0.84°/nm covering the whole 28.6° steering range is obtained. This work theoretically verifies the feasibility of integrating an OPA scanner into the GaSb-based SE-ICLs, providing a practical solution to fabricate compact steerable MIR laser sources. Note that this substrate OPA concept has strong adaptation potential to extend to even longer wavelength devices such as InP and GaAs-based quantum cascade lasers.
Extreme learning machine and genetic algorithm in quantitative analysis
of sulfur hexafluoride by infrared spectroscopy
Authors: Liu Huan , Zhu Jun , Yin Huan , Yan Qiangqiang , Liu Hong , Guan Shouxin , Cai Qisheng , Sun Jiawen , Yao Shun , Wei Ruyi
Published: March 2022

Owing to the general disadvantages of traditional neural networks in gas concentration
inversion, such as slow training speed, sensitive learning rate
selection, unstable solutions, weak generalization ability, and an
ability to easily fall into local minimum points, the extreme learning
machine (ELM) was applied to sulfur hexafluoride (

S
F

6

) concentration inversion research. To
solve the problems of high dimensionality, collinearity, and noise of
the spectral data input to the ELM network, a genetic algorithm was
used to obtain fewer but critical spectral data. This was used as an
input variable to achieve a genetic algorithm joint extreme learning
machine (GA-ELM) whose performance was compared with the genetic
algorithm joint backpropagation (GA-BP) neural network algorithm to
verify its effectiveness. The experiment used 60 groups of

S
F

6

gas samples with different
concentrations, made via a self-developed Fourier transform infrared
spectroscopy instrument. The

S
F

6

gas samples were placed in an open
optical path to obtain infrared interference signals, and then
spectral restoration was performed. Fifty groups were randomly
selected as training samples, and 10 groups were used as test samples.
The BP neural network and ELM algorithms were used to invert the

S
F

6

gas concentration of the mixed
absorbance spectrum, and the results of the two algorithms were
compared. The sample mean square error decreased from 248.6917 to
63.0359; the coefficient of determination increased from 0.9941 to
0.9984; and the single running time decreased from 0.0773 to 0.0042 s.
Comparing the optimized GA-ELM algorithm with traditional algorithms
such as ELM and partial least squares, the GA-ELM algorithm had higher
prediction accuracy and operating efficiency and better stability and
generalization performance in the quantitative analysis of small
samples of gas under complex noise backgrounds.
Identification of DAPI-stained normal, inflammatory, and carcinoma hepatic cells based on hyperspectral microscopy
Authors: Lin Sifan , Ke Ze , Liu Kunxing , Zhu Siqi , Li Zhen , Yin Hao , Chen Zhenqiang
Published: March 2022

Gross chromatin imbalance and high DNA content are distinct features of various types of cancer cells. However, severe inflammation can also produce similar symptoms in cells. In this study, normal, inflammatory, and carcinoma hepatic cells were stained with 4’,6-diamidino-2-phenylindole (DAPI) and investigated by hyperspectral microscopy. DAPI is a DNA-sensitive fluorochrome. Therefore, the differences in the cellular DNA of the samples can be revealed by the corresponding fluorescence. Our experimental results demonstrate that although chromosomal disorder and high DNA content both occur in severely inflammatory and carcinoma hepatic cells, there is still a slight difference in their DNA, making their fluorescent intensity and even their spectral shapes distinguishable. Based on these spectral features, we developed a method for the precise identification of normal, inflammatory, and carcinoma hepatic cells in the field of view. The identification accuracy for these three types of cells was 99.8%. We believe that examination that combines DAPI staining with hyperspectral microscopy is a potential method for the identification and investigation of various types of cancer tissues.
Miniaturized cost-effective broadband spectrometer employing a deconvolution reconstruction algorithm for resolution enhancement
Authors: Shcheglov Artem , Nie Yunfeng , Schretter Colas , Heeman Rob , van der Put Arthur , Hoving Willem , Thienpont Hugo , Schelkens Peter , Ottevaere Heidi
Published: March 2022

We demonstrate a miniaturized broadband spectrometer employing a reconstruction algorithm for resolution enhancement. We use an opto-digital co-design approach, by firstly designing an optical system with certain residual aberrations and then correcting these aberrations with a digital algorithm. The proposed optical design provides an optical resolution less than 1.7 nm in the VIS-channel (400-790 nm) and less than 3.4 nm in the NIR-channel (760-1520 nm). Tolerance analysis results show that the components are within a commercial class, ensuring a cost-efficient design. We build the prototype with a size of 37x30x26 mm3 and demonstrate that by applying a restoration algorithm, the optical resolution can be further improved to less than 1.3 nm (VIS-channel) and less than 2.3 nm (NIR-channel).
Angular multiplexation of partial helical phase modes in orbital angular momentum holography
Authors: Wang Feili , Zhang Xiangchao , Xiong Rui , Ma Xinyang , Jiang Xiangqian
Published: March 2022

The orbital angular momentum (OAM) holography has been identified as a vital approach for achieving ultrahigh-capacity multiplexation without a theoretical helical phase index limit. However, the encoding and decoding of an OAM hologram require a complete helical phase mode, which does not take full utilization of the angular space. In this paper, the partial OAM holography is proposed by dividing an OAM mode into several partial orbital angular momentums and encode each partial mode with a different target image. An image can only be reconstructed using an appropriate partial OAM mode within a specific illuminating angular range, henceforth holographic multiplexation of images can be realized. This method can significantly increase the holographic information capacity and find widespread applications.
Detection of ionized air using a photonic-crystal nanocavity excited by broadband light from a superluminescent diode
Authors: Takahashi Yuki , Fujimoto Masanao , Kikunaga Kazuya , Takahashi Yasushi
Published: March 2022

It has been shown that silicon photonic crystal nanocavities excited by spectrally narrow light can be used to detect ionized air. Here, to increase the range of possible applications of nanocavity-based sensing, the use of broadband light is considered. We find that the use of a superluminescent diode (SLD) as an excitation source enables a more reproducible detection of ionized air. When our photonic-crystal nanocavity is exposed to ionized air, carriers are transferred to the cavity and the light emission from the cavity decreases due to free carrier absorption. Owing to the broadband light source, the resonance wavelength shifts caused by the carriers in this system (for example, due to temperature fluctuations) do not influence the emission intensity. SLD-excited cavities could be useful to determine the density of ions in air quantitatively.
Investigation of bound states in the continuum in dual-band perfect absorbers
Authors: Gao Enduo , Li Hongjian , Liu Zhimin , Xiong Cuixiu , Liu Chao , Ruan Banxian , Li Min , Zhang Baihui
Published: March 2022

Enhancing the light-matter interaction of two-dimensional materials in the visible and near-infrared regions is highly required in optical devices. In this paper, the optical bound states in the continuum (BICs) that can enhance the interaction between light and matter are observed in the grating-graphene-Bragg mirror structure. The system can generate a dual-band perfect absorption spectrum contributed by guided-mode resonance (GMR) and Tamm plasmon polarition (TPP) modes. The optical switch can also be obtained by switching the TE-TM wave. The dual-band absorption response is analyzed by numerical simulation and coupled-mode theory (CMT), with the dates of each approach displaying consistency. Research shows that the GMR mode can be turned into the Fabry-Pérot BICs through the transverse resonance principle (TRP). The band structures and field distributions of the proposed loss system can further explain the BIC mechanism. Both static (grating pitch P) and dynamic parameters (incident angle θ) can be modulated to generate the Fabry-Pérot BICs. Moreover, we explained the reason why the strong coupling between the GMR and TPPs modes does not produce the Friedrich-Wintgen BIC. Taken together, the proposed structure can not only be applied to dual-band perfect absorbers and optical switches but also provides guidance for the realization of Fabry-Pérot BICs in lossy systems.
Parametric characterization of ground surfaces with laser speckles
Authors: Schweickhardt León , Tausendfreund Andreas , Stöbener Dirk , Fischer Andreas
Published: March 2022

With well-known speckle measurement techniques, the root mean square height as well as the autocorrelation length of isotropic surfaces can be determined quickly and over a large area of interest. Beyond that, the present article studies the speckle-based measurement of anisotropic surfaces. For this purpose, a measurement setup and evaluation algorithm are presented that enable the characterization of unidirectionally anisotropic surfaces machined by grinding. As a result, four measurands are obtained from one speckle image: the machining direction, the autocorrelation length perpendicular to the machining direction, as well as two root mean square roughness parameters parallel and perpendicular to the machining direction. The first two measurands are obtained from a two-dimensional fast Fourier transform of the diffraction pattern resulting from the unidirectional tool marks and the latter two by a bidirectional evaluation of the speckle contrast. In addition to measurements on physical reference samples, a spatial light modulator is used to create a large number of surface topographies with known model parameters in order to quantify the measurement uncertainty.
Artificial neural networks for material parameter extraction in terahertz time-domain spectroscopy
Authors: Klokkou Nicholas , Gorecki Jon , Wilkinson James S. , Apostolopoulos Vasilis
Published: March 2022

Terahertz time-domain spectroscopy (THz-TDS) is a proven technique whereby the complex refractive indices of materials can be obtained without requiring the use of the Kramers-Kronig relations, as phase and amplitude information can be extracted from the measurement. However, manual pre-processing of the data is still required and the material parameters require iterative fitting, resulting in complexity, loss of accuracy and inconsistencies between measurements. Alternatively approximations can be used to enable analytical extraction but with a considerable sacrifice of accuracy. We investigate the use of machine learning techniques for interpreting spectroscopic THz-TDS data by training with large data sets of simulated light-matter interactions, resulting in a computationally efficient artificial neural network for material parameter extraction. The trained model improves on the accuracy of analytical methods that need approximations while being easier to implement and faster to run than iterative root-finding methods. We envisage neural networks can alleviate many of the common hurdles involved in analyzing THz-TDS data such as phase unwrapping, time domain windowing, slow computation times, and extraction accuracy at the low frequency range.
Nonlinearity-mediated collimation of optical beams
Authors: Liang Guo , Shu Fangjie , Cheng Wenjing , Jiao Longbo
Published: March 2022

We investigated the evolutions of optical beams in an optical system composed of free spaces and nonlocal nonlinear media layers in a cascaded manner. From an application point of view, two kinds of evolution processes for Gaussian beams, nonlinearity-mediated collimation and switching from breathers to solitons, were discussed in details. By adjusting the input optical power, the collimating, the compressing and the expanding of optical beams are convenient to be controlled.
Deep learning adapted acceleration for limited-view photoacoustic image reconstruction
Authors: Lan Hengrong , Gong Jiali , Gao Fei
Published: March 2022

The limited-view issue can cause a low-quality image in photoacoustic (PA) computed tomography due to the limitation of geometric condition. The model-based method is used to resolve this problem, which contains different regularization. To adapt fast and high-quality reconstruction of limited-view PA data, in this Letter, a model-based method that combines the mathematical variational model with deep learning is proposed to speed up and regularize the unrolled procedure of reconstruction. A deep neural network is designed to adapt the step of the gradient updated term of data consistency in the gradient descent procedure, which can obtain a high-quality PA image with only a few iterations. A comparison of different model-based methods shows that our proposed scheme has superior performances (over 0.05 for SSIM) with the same iteration (three times) steps. Finally, we find that our method obtains superior results (0.94 value of SSIM for in vivo) with a high robustness and accelerated reconstruction.
Tunable terahertz Bessel beams with orbital angular momentum
Authors: Miyamoto Katsuhiko , Nomura Riku , Tsurumaru Shohei , Omatsu Takashige
Published: March 2022

In this work we demonstrate a frequency-tunable terahertz (THz) Bessel beam with zero- and first- order modes and orbital angular momentum, by utilizing a Tsurupica Axicon lens in combination with a picosecond difference frequency generation laser. This system enabled the selective generation of zero- or first-order THz Bessel beams with frequency-tunability across the range 3–7 THz.
The transcription factor HLH-26 controls probiotic-mediated protection against intestinal infection through up-regulation of the Wnt/BAR-1 pathway
Authors: Sang Yu , Ren Jie , Aballay Alejandro
Published: March 2022

Probiotics play a critical role in the control of host intestinal microbial balance, protecting the host from gastrointestinal pathogens, modulating the host immune response, and decreasing host susceptibility to infection. To understand the mechanism underlying the protective effect of probiotics against infections through immune regulation, we examined protection against Salmonella enterica infection following exposure to nonpathogenic Enterococcus faecium in the nematode Caenorhabditis elegans. We found that the transcription factor HLH-26, a REF-1 family member of basic helix–loop–helix transcription factors, was required in the intestine for E. faecium–mediated protection of C. elegans against a lethal S. enterica infection. In addition, we uncovered that defense response genes controlled by the canonical Wnt/BAR-1 pathway were activated upon exposure to E. faecium in an HLH-26–dependent manner. Our findings highlight a role for REF-1/HLH-26 in the control of the Wnt/BAR-1 pathway in probiotic-mediated protection against gut infection.
Base-resolution prediction of transcription factor binding signals by a deep learning framework
Authors: Zhang Qinhu , He Ying , Wang Siguo , Chen Zhanheng , Guo Zhenhao , Cui Zhen , Liu Qi , Huang De-Shuang
Published: March 2022

Transcription factors (TFs) play an important role in regulating gene expression, thus the identification of the sites bound by them has become a fundamental step for molecular and cellular biology. In this paper, we developed a deep learning framework leveraging existing fully convolutional neural networks (FCN) to predict TF-DNA binding signals at the base-resolution level (named as FCNsignal). The proposed FCNsignal can simultaneously achieve the following tasks: (i) modeling the base-resolution signals of binding regions; (ii) discriminating binding or non-binding regions; (iii) locating TF-DNA binding regions; (iv) predicting binding motifs. Besides, FCNsignal can also be used to predict opening regions across the whole genome. The experimental results on 53 TF ChIP-seq datasets and 6 chromatin accessibility ATAC-seq datasets show that our proposed framework outperforms some existing state-of-the-art methods. In addition, we explored to use the trained FCNsignal to locate all potential TF-DNA binding regions on a whole chromosome and predict DNA sequences of arbitrary length, and the results show that our framework can find most of the known binding regions and accept sequences of arbitrary length. Furthermore, we demonstrated the potential ability of our framework in discovering causal disease-associated single-nucleotide polymorphisms (SNPs) through a series of experiments.
Household treatment cost of breast cancer and cost coping strategies from a tertiary facility in Ghana
Authors: Adanu Kekeli Kodjo , Bansah Eyram Cyril , Adedia David , Aikins Moses
Published: March 2022

Breast cancer is the number one cause of cancer death in women globally. According to the Global cancer registry, there were 2.3 million new cases of breast cancer diagnosed in 2020 worldwide, accounting for 25% of all cancer cases in women. The data on the cost burden of breast cancer on households is limited in Ghana, it is therefore imperative that it is estimated to ensure effective planning and provision of adequate resources for breast cancer treatment. This cost-of-illness study estimates the household treatment cost of breast cancer and the cost coping strategies used by patients. This cost-of-illness study was conducted at the surgical unit (Surgical unit 2) of the Korle Bu Teaching Hospital (KBTH), with 74 randomly selected patients and their accompanying caregiver(s). Data was collected using structured questionnaire on direct, indirect and intangible costs incurred and coping strategies used by patients and their households. The results are presented in descriptive and analytic cost statistics. Most of the patients were aged 40–69 years and were married with moderate education levels. Nearly 57% of patients earn an income of USD 370 or less per month. The average household expenditure was USD 990.40 (medical cost: USD 789.78; non-medical cost: USD 150.73; and indirect cost: USD 50). The publicly provided mechanism was the most utilized cost coping strategy. The direct, indirect and intangible costs associated with breast cancer treatment had significant financial and psychological implications on patients and their households. Moreover, poorer families are more likely to use the publicly provided strategies to cope with the increasing cost of breast cancer treatment.