bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Physics Modeling Study of COVID-19 Transport in Air
Authors: Anchordoqui Luis Alfredo , Dent James B. , Weiler Thomas J. 
Published: October 2020

Objectives: Health threat from COVID-19 airborne infection has become a public emergency of international concern. During the ongoing coronavirus pandemic, people have been advised by the Centers for Disease Control and Prevention to maintain social distancing of at least 2 m to limit the risk of exposure to the coronavirus. Experimental data, however, show that infected aerosols and droplets trapped inside a turbulent puff cloud can travel 7 to 8 m. We carry out a physics modeling study for COVID-19 transport in air. Methodology: We propose a nuclear physics analogy-based modeling of the complex gas cloud and its payload of pathogen-virions. We estimate the puff effective stopping range adapting the high-energy physics model that describes the slow down of α-particles (in matter) via interactions with the electron cloud. Analysis Findings: We show that the cloud stopping range is proportional to the diameter of the puff times its density. We use our puff model to determine the average density of the buoyant fluid in the turbulent cloud. A fit to the experimental data yields , where and are the average density of the puff and the air. We demonstrate that temperature variation could cause an O (≲ ±8%) effect in the puff stopping range for extreme ambient cold or warmth. We also demonstrate that aerosols and droplets can remain suspended for hours in the air. Therefore, once the puff slows down sufficiently, and its coherence is lost, the eventual spreading of the infected aerosols becomes dependent on the ambient air currents and turbulence.
Factores maternos asociados al peso al nacer del recién nacido en embarazadas adolescentes de Salta- Capital. Argentina. Años 2002-2011.
Authors: Zimmer Sarmiento Maria  del Carmen , Oyes Lopez Ontivero Julio Cesar 
Published: October 2020

Resumen Introducción: En Argentina, el embarazo adolescente es un problema de salud pública, con serias implicaciones en la salud y nutrición del binomio madre-hijo. Objetivo: objetivo del estudio fue evaluar características maternas de adolescentes embarazadas y asociarlos con el peso de los recién nacidos. Material y método: Se realizó un estudio descriptivo de corte transversal con 9479 embarazadas del Hospital Público Materno Infantil de Salta, Capital. Se determinó asociación del peso al nacer con las variables explicativas (edad, estatura, IMC, nivel de instrucción de la madre, edad gestacional, control prenatal, y sexo del recién nacido) a través de chi cuadrado, T student o anova en cada caso específico. Resultados: Se encontró asociación estadísticamente significativa entre el peso al nacer y las características maternas y del recién nacido estudiadas a excepción de la edad de embarazadas (temprana y tardía) en adolescentes. Conclusiones: Este estudio evidencia la asociación entre el peso al nacer tanto con las características biológicas y sociales de la madre y, del neonato, como así también el control prenatal. Palabras clave: Factores maternos- Embarazo adolescente- Peso al nacer Abstract:Introduction: In Argentina, teenage pregnancy is a public health problem, with serious health and nutrition implications of the mother-child binomial. Objective: The objective of the study was to evaluate maternal characteristics of pregnant adolescents and associate them with the weight of newborns. Material and method: A descriptive cross-sectional study was carried out with 9479 pregnant women from the Maternal and Child Public Hospital in Salta, Capital. Association of birth weight with explanatory variables (age, height, BMI, level of instruction of the mother, gestational age, prenatal control, and sex of the newborn) was determined through chi square, T student or anova in each specific case. Results: A statistically significant association was found between birth weight and maternal and newborn characteristics studied, except for the age of pregnant women (early and late) in adolescents. Conclusions: This study evidences the association between birth weight with both the biológica and social characteristics of the mother and the newborn, as well as prenatal control. key words: Maternal factors- Teen pregnancy- Birth weight
A continuant and an estimate of the remainder of the interpolating continued C-fraction
Authors: Pahirya M.M. 
Published: October 2020

The problem of the interpolation of functions of a real variable by interpolating continued $C$-fraction is investigated. The relationship between the continued fraction and the continuant was used. The properties of the continuant are established. The formula for the remainder of the interpolating continued $C$-fraction proved. The remainder expressed in terms of derivatives of the functional continent. An estimate of the remainder was obtained. The main result of this paper is contained in the following Theorem 5:Let \(\mathcal{R}\subset \mathbb{R} \) be a compact, \(f \in \mathbf{C}^{(n+1)}(\mathcal{R})\) andthe interpolating continued $C$-fraction~($C$-ICF) of the form$$D_n(x)=\frac{P_n(x)}{Q_n(x)}=a_0+\bfrac{K}{k=1}{n}\frac{a_k(x-x_{k-1})}{1}, \ a_k \in \mathbb{R}, \; k=\overline{0,n},$$be constructed by the values the function \(f\) at nodes $X=\{x_i : x_i \in \mathcal{R}, x_i\neq x_j, i\neq j, i,j=\overline{0,n}\}.$If the partial numerators of $C$-ICF satisfy the condition of the Paydon--Wall type, that is\(0<a^* \ {\rm diam}\, \mathcal{R} \leq p\), then$\displaystyle|f(x)-D_n(x)|\leq \frac{f^*\prod\limits_{k=0}^n |x-x_k|}{(n+1)!\, \Omega_n(t)} \Big( \kappa_{n+1}(p)+\sum_{k=1}^r \tbinom{n+1}{k} (a^*)^k \sum_{i_1=1}^{n+1-2k} \kappa_{i_1}(p)\times$$\displaystyle\times \sum_{i_2=i_1+2}^{n+3-3k} \kappa_{i_2-i_1-1}(p)\dots\sum_{i_{k-1}=i_{k-2}+2}^{n-3} \kappa_{i_{k-1}-i_{k-2}-1}(p)\sum_{i_k=i_{k-1}+2}^{n-1} \kappa_{i_k-i_{k-1}-1}(p)\, \kappa_{n-i_{k}}(p)\Big),$ where $\displaystyle f^*=\max\limits_{0\leq m \leq r}\max\limits_{x \in \mathcal{R}} |f^{(n+1-m)}(x)|,$$\displaystyle \kappa_n(p)=\cfrac{(1\!+\!\sqrt{1+4p})^n\!-\!(1\!-\!\sqrt{1+4p})^n}{2^n\, \sqrt{1+4p}},$\ $a^*=\max\limits_{2\leqslant i \leqslant n}|a_i|,$\ $p=t(1-t),\;t\in(0;\tfrac{1}{2}], \; r=\big[\tfrac{n}{2}\big].$
Variable presentation of diabetic papillopathy and treatment dilemma- A case series
Authors: Kumari Archana , Agarwal Lalit , Agrawal Nisha , Prasad Indranath , Aditya Kshitij , Pradhan Deepti 
Published: October 2020

Introduction: Diabetic papillopathy (DP) is a diagnosis of exclusion in type 1 and type 2 diabetics with transient disc edema. It was initially described in young patients with type1 diabetes mellitus (DM) as a bilateral disease with minimal visual symptoms which resolved spontaneously. Lately, DP has been a focus of controversy because of its wide clinical spectrum.
Cases: We describe three variable cases of DP. These are unilateral DP with Proliferative Diabetic Retinopathy (PDR) with macular edema (ME), unilateral DP with severe Non Proliferative Diabetic Retinopathy (NPDR) with ischemic maculopathy and a case of bilateral DP with Moderate NPDR with ME. We also discuss viable treatment for the variable presentation. DP has been reported in this case series in moderate NPDR, severe NPDR as well as PDR. Macular involvement in the form of macular edema as well as ischemia has been demonstrated to result in diminution of vision. It shows both unilateral and bilateral presentation. Remarkable visual loss seen, in these cases, call for intervention.
Conclusions: DP has a wide spectrum of presentation and its knowledge is eminent to make a complete diagnosis. Individualisation of treatment has to be done for variable presentation and realistic outcomes should be explained to the patients.
Fluorophotometric Measurement of Corneal Autofluorescence in Diabetic and Normal Eyes
Authors: Srinivasan Ramyaa , Bhandari Madhavendra , Sharma Tarun , Raman Rajiv 
Published: October 2020

Introduction: Corneal autofluorescence (AF) has been recommended as an indicator of diabetic retinopathy. This study was conducted to evaluate corneal autofluorescence in non-insulin dependent diabetes subjects (with and without diabetic retinopathy) and compare the changes with healthy subjects.
Materials and methods: In this cross-sectional study, 145 eyes of diabetes mellitus subjects with and without diabetic retinopathy and 34 eyes of normal healthy subjects were included. Diabetic patients were subdivided by the severity of retinopathy based on international clinical diabetic retinopathy disease severity scale. The investigations included fluorophotometric determination of corneal autofluorescence, fasting glucose level (FBS) and glycosylated hemoglobin (HbA1c).
Results: The corneal autofluorescence values were significantly higher in moderate NPDR, severe NPDR and PDR when compared with healthy subjects (p<0.001). FBS values and HbA1c were significantly higher in all diabetic groups than the healthy subjects (p<0.001). In linear regression test, corneal autofluorescence seem to be related to duration of diabetes and FBS, but not with age and HbA1c.
Conclusion: We conclude that the level of corneal autofluorescence is dependent on the severity of diabetic retinopathy. Our study suggests that the formation of autofluorescent products in cornea depend upon the glucose concentration in the aqueous humor.
Evaluation of change in pterygium induced keratometric astigmatism in patients following pterygium excision with autologous graft surgery
Authors: Jain Amit Kumar , Pandey Dadan Ji 
Published: October 2020

Introduction: Pterygium is a common surface disorder of the eye that may cause change in visual acuity of patients by inducing astigmatic refractive error. Surgical excision with grafting is considered the most effective recommended treatment for pterygium. The objective of this study was to evaluate the outcomes of pterygium excision with autologous graft surgery on keratometric astigmatism and visual acuity.
Materials and methods: In this study total 64 eyes of 64 patients were enrolled having the diagnosis of pterygium. Prior to the pterygium excision surgery all the enrolled patients were studied for grading of pterygium, clinical symptoms, keratometric values and best corrected visual acuity (BCVA). Postoperatively, BCVA and keratometric readings were recorded at one week, one month, two months and four months intervals.
Results: Mean age of study participants was 34.16 ± 8.24 years in the age group of 18-60 years. 42 (65.62%) eyes had grade II pterygium, while 16 (25.0 %) and 6 (9.38%) eyes were having grade III and grade IV pterygium, respectively. Preoperative median and quartiles (25% -75%) horizontal and vertical keratometric values were 43.00 (42.50-44.00) D and 44.25 (43.75-44.50) D, respectively and both reduced significantly to 42.50 (42.50-42.94) D and 42.50 (42.50- 43.00) D, respectively after four months postoperatively. Median keratometric astigmatism before surgery was 1.37 (1.25-1.93) D which reduced significantly to 0.50 (0.32-0.75) D after four months of pterygium excision. Similarly, BCVA improved significantly [0.20(0.16-0.25) vs 0.53 (0.50-0.80)] when assessed postoperatively after four months.
Conclusion: Excision of pterygium with autologous graft reduced pterygium-induced keratometric astigmatism and improved BCVA significantly.
Profile of Ophthalmic Tumors in Adult Nepalese Population in Central Nepal
Authors: Pant Nayana , Shrestha Gulshan Bahadur , Joshi Sagun Narayan , Bhatta Subash 
Published: October 2020

Introduction: Ophthalmic tumors cover benign and malignant tumors of eyelids, conjunctiva, globe, and orbit. There is limited literature on ophthalmic tumors in Nepal. The objective of the study was to find the relative frequency of various ophthalmic tumors in the adult Nepalese population in Central Nepal.
Material and methods: This is an observational descriptive study. A total of 100 consecutive patients, presenting with ophthalmic tumors to tertiary referral eye hospital were enrolled for the study. Demographic profile, detailed history, clinical features and diagnosis of the ophthalmic tumors were recorded. The tissue from incisional or excisional biopsy was then subjected to histopathological examination for confirmatory diagnosis.
Results: Mean age of subjects with ophthalmic tumors was 51.5 ± 18.2 years with a female to male ratio of 1.2:1. Benign tumors (64%) were the most common tumors followed by malignant (26%) and premalignant tumors (10%). Most common benign tumor was naevus (26.5%); most common premalignant tumor was conjunctival intraepithelial neoplasia (60%), and most common malignant tumor was sebaceous gland carcinoma (30.8%). Eyelid was most frequently involved with ophthalmic tumors (59%) followed by conjunctiva (21%). Clinical diagnosis correlated with histopathological diagnosis in 77% of cases.
Conclusion: As different ophthalmic tumors present in a myriad of ways and a significant proportion of these cases presenting to hospital settings are malignant, it is prudent to confirm with a histopathological diagnosis for optimum management of such cases.
Perception and Willingness towards Eye Donation in an urban community of West Bengal
Authors: Gupta Shibaji , Kole Seshadri , Bhattacharya Saikat , Guchhait Debjani 
Published: October 2020

Introduction: Corneal blindness, though treatable, contributes largely to the burden of blindness. With 1.2 million existing cases of corneal blindness in India, the demand for cornea collection is increasing. 69349 corneas were collected in 2018-19 but it is much less than what is needed. Faulty perceptions and unwillingness are two major hurdles against a scenario favourable towards eye donation. The objectives of the study was to assess the perception and willingness towards eye donation and the socio-demographic variables that affect such perception and willingness, in an urban community of West Bengal.
Materials and methods: In this cross-sectional study conducted among adult residents of the urban field practice area of Medical College Kolkata, data was collected from randomly selected eligible members, one each from all the available families by interviewing them using a validated pre tested schedule.
Results: Eighty nine (52.3%) among 170 interviewed participants had Secondary level education or higher, 49.4% had outdoor engagement. 128 participants reported ocular morbidity in the family but only 126 had heard about eye donation. 98 (77.8%) of these 126, had favourable perception towards eye donation. Among these 98 participants, 40 were willing to pledge for eye donation. Higher education and outdoor engagement significantly predicted favourable perception, while willingness significantly increased with participants belonging to higher socio-economic class and with higher education.
Conclusions: Compared to favourable perception, willingness of pledging eyes was lesser due to various false notions. Proper education through usage of means of mass communication and stress upon school education is needed to address these hurdles.
Diagnostic features of the presumed focal viral retinitis: A case series
Authors: Manandhar Anu 
Published: October 2020

Introduction: Other than well-known herpetic retinopathies like acute retinal necrosis, progressive outer retinal necrosis and cytomegalovirus retinitis, there are few reports on atypical forms of viral retinitis caused by herpes virus from around the world.
Cases: Presenting symptom was sudden onset of diminution of vision in all 6 cases. Mean duration of symptoms at presentation was 7.6 days. The mean age was 27.3 years (range 22-40 years). All were immunocompetent (4 females and 2 males), with unremarkable review of system. All had unilateral involvement. Presenting visual acuity ranged from CFCF to 6/60. Granulomatous anterior uveitis was present in 4 cases. All had focal retinitis with irregular margins, either juxtapapillary, macular or over one of the major vascular arcades. The diagnosis of focal viral retinitis was made solely based upon the clinical findings. All recovered after a course of oral acyclovir (one was given additional intravitreal acyclovir as well) and oral prednisolone, with final visual acuity of 6/6P to 6/9 in all except one.
Conclusion: In case of focal retinitis with irregular margin, viral etiology should be borne in mind. Clinical features are typical enough to help in diagnosing without PCR test.
Odczytując palimpsest miejski. Na przykładzie Katowic
Authors: Węgrzynek Krystian 
Published: October 2020

The article invites the readers to approach the city itself as a text of culture. We are to read it alongside other narratives/narrations (literary, artistic, and cinematic) devoted to it. The author traces how Katowice’s space has been transmuted into politically- and culturally-charged places, by distinguishing consecutive layers of the palimpsest (Polish village, building patterns of German and Polish times: the old and the new). The foregoing examples allow the author to indicate the traces of conceptions and ideologies reflected by architecture. He also includes some methodological recommendations/tips pertaining to reading the space.
Free vibration of bidirectional functionally graded sandwich beams using a first-order shear deformation finite element formulation
Authors: Anh Le Thi Ngoc , Ninh Vu Thi An , Lang Tran Van , Kien Nguyen Dinh 
Published: October 2020

Free vibration of bidirectional functionally graded sandwich (BFGSW) beams is studied by using a first-order shear deformation finite element formulation. The beams consist of three layers, a homogeneous core and two functionally graded skin layers with material properties varying in both the longitudinal and thickness directions by power gradation laws. The finite element formulation with the stiffness and mass matrices evaluated explicitly is efficient, and it is capable of giving accurate frequencies by using a small number of elements. Vibration characteristics are evaluated for the beams with various boundary conditions. The effects of the power-law indexes, the layer thickness ratio, and the aspect ratio on the frequencies are investigated in detail and highlighted. The influence of the aspect ratio on the frequencies is also examined and discussed.
Keywords:
BFGSW beam; first-order shear deformation theory; free vibration; finite element method.
Ảnh hưởng của độ gồ ghề đến một số đặc tính thuỷ lực của vật liệu rỗng có chứa vết nứt đơn
Authors: Tuấn Trần Anh , Hải Nguyễn Đình 
Published: October 2020

Bài báo này trình bày mô phỏng số dòng Stokes đi qua vết nứt đơn, gồ ghề xuất hiện trong môi trường vật liệu rỗng, ở đó hai hình thái gồ ghề được xem xét đó là: dạng hình sin và dạng tam giác. Trong nghiên cứu này, một số đặc tính thuỷ lực của dòng Stokes như trường vận tốc và áp suất trước tiên phải được xác định bằng cách sử dụng phương pháp phần tử biên, sau đó các nghiệm số thu được được sử dụng để tính toán độ thấm hữu hiệu của vết nứt trong vật liệu rỗng. Ảnh hưởng của mức độ gồ ghề và độ mở rộng của vết nứt lên độ thấm hữu hiệu được xem xét và phân tích. Nhằm mục đính chứng minh tính chính xác và hiệu quả của phương pháp đã đề xuất, các kết quả thu được cho trường vận tốc và áp suất được so sánh với kết quả thu được bằng phương pháp phần tử hữu hạn.
Từ khóa:
vật liệu rỗng bị nứt; dòng Stokes; phương pháp phần tử biên; độ thấm hữu hiệu; vết nứt gồ ghề.
Ảnh hưởng của động đất tác dụng dọc nhà đối với kết cấu thép nhà công nghiệp một tầng có cầu trục
Authors: Thuật Đinh Văn , Hòa Nguyễn Đình , Cường Nguyễn Văn , Hùng Trương Việt 
Published: October 2020

Trong bài báo này, tám kết cấu nhà công nghiệp một tầng một nhịp bằng thép có cầu trục được khảo sát theo sơ đồ phân tích không gian chịu tải trọng động đất tĩnh tương đương tác dụng theo phương dọc nhà (PDN). Các thông số khảo sát gồm nhịp khung 20, 26, 32 và 38 m; sức trục 100 và 200 kN; địa điểm xây dựng ở Hà Nội và Sơn La. Kết quả tính cho thấy mô men uốn lớn nhất ở chân cột theo phương ngoài mặt phẳng khung ngang do thành phần tải trọng động đất tác dụng theo PDN là rất nhỏ và có thể bỏ qua, trong khi lực nén trong cột lại khá lớn, đặc biệt ở những cột thuộc khoang có giằng cột. Xét trường hợp tổ hợp nội lực do tĩnh tải và động đất, lực nén trong cột khi xét cả ba thành phần động đất tác dụng theo phương ngang, đứng và dọc nhà là lớn hơn từ 2,36 đến 2,99 lần so với trường hợp chỉ xét theo phương ngang và đứng. Kết quả đã chỉ ra ảnh hưởng của tải trọng động đất tác dụng theo PDN đã làm tăng đáng kể lực nén trong cột, đặc biệt đối với những cột ở khoang có giằng cột và điều này cần phải được kể đến trong tính toán thiết kế kết cấu nhà công nghiệp một tầng bằng thép có cầu trục chịu động đất. Mức độ tăng giá trị lực nén trong cột phụ thuộc vào chiều dài nhịp và cường độ tác động của động đất.
Từ khóa:
nhà công nghiệp một tầng; phân tích không gian; khung thép; chiều dài nhịp: tải trọng động đất; phương dọc nhà.
Nghiên cứu giải pháp thiết kế các cấu kiện hố trồng cây bằng bê tông cốt thép có khả năng thu thoát nước mưa cho đường phố đô thị
Authors: Tân Nguyễn Ngọc , Phương Nguyễn Việt , Đức Ngô Việt , Minh Phan Quang 
Published: October 2020

Nghiên cứu này giới thiệu giải pháp thiết kế hố trồng cây bằng kết cấu bê tông cốt thép có khả năng thu thoát nước mưa cho đường phố đô thị. Ba loại cấu kiện hố trồng cây đã được đề xuất, đó là: (i) hố trồng cây dạng đơn không đáy, (ii) hố trồng cây kết hợp hố ga thu nước đặt trên vỉa hè, (iii) hố trồng cây kết hợp hố ga thu nước đặt dưới đường. Hố trồng cây được thiết kế với các kích thước điển hình (chiều dài × chiều rộng × chiều cao) lần lượt là 1200 × 1200 × 900 mm, 1400 × 1400 × 1100 mm và 1600 × 1600 × 1200 mm. Một cấu kiện hố trồng cây dạng đơn không đáy đã được chế tạo bằng bê tông có cấp độ bền B30 và lưới thép Φ6a80 để ứng dụng thử nghiệm vào thực tế. Trên đường phố đô thị, các kết cấu hố trồng cây được kết nối với hệ thống thoát nước, cho phép cải thiện khả năng thoát nước mưa và hoạt động như một bể thấm lọc sinh học.
Từ khóa:
hố trồng cây; bê tông cốt thép; hệ thống thoát nước bền vững; đường phố đô thị.
Chẩn đoán hư hỏng trong kết cấu tấm sử dụng phương pháp năng lượng biến dạng kết hợp với thuật toán di truyền
Authors: Cao Lê Thanh , Sỹ Bạch Văn , Duy Hồ Đức 
Published: October 2020

Bài báo này đề xuất một phương pháp chẩn đoán hư hỏng về cả vị trí và mức độ của hư hỏng cho kết cấu tấm thông qua quy trình chẩn đoán hai bước. Trong bước thứ nhất, chỉ tiêu dựa vào sự thay đổi của năng lượng biến dạng “Modal Strain Energy Damage Index – MSEDI” được sử dụng để chẩn đoán vị trí của hư hỏng. Giá trị năng lượng biến dạng được xác định từ kết quả phân tích dao động của kết cấu tấm ở hai trạng thái trước và sau khi xuất hiện hư hỏng. Trong bước thứ hai, thuật toán di truyền được sử dụng để cực tiểu hóa hàm mục tiêu với biến số là véc-tơ mức độ suy giảm chiều dày của các phần tử có khả năng xảy ra hư hỏng đã được cảnh báo từ bước thứ nhất. Hàm mục tiêu được sử dụng cũng dựa trên giá trị năng lượng biến dạng. Tính hiệu quả của phương pháp đề xuất được khảo sát và đánh giá thông qua bài toán tấm với các kịch bản hư hỏng khác nhau. Kết quả phân tích cho thấy, phương pháp đề xuất có khả năng chẩn đoán chính xác sự xuất hiện, vị trí và độ lớn của hư hỏng trong kết cấu tấm.
Từ khóa:
chẩn đoán hư hỏng; dao động; kết cấu tấm; năng lượng biến dạng; thuật toán di truyền.
Design and development of wireless power transfer system for implantable cardioverter defibrillator
Authors: Aditya Kuragayala , Bobba Phaneendra Babu , Satyavani Yadlapalli 
Published: October 2020

Wireless power transfer system is playing an important role in biomedical applications by transferring power wirelessly to the implants present in the body. In this paper, magnetic coupling resonance wireless power transfer system is used to recharge battery of implantable cardioverter defibrillator. The proposed system operates at 300 KHz frequency. The LCC-C compensation topology is used to tune the coils for operating the system at stable resonant frequency and to obtain higher efficiency. In this paper, we have investigated the performance of different coil structures in multiple layer configurations and we offer recommendations on the best suitable configuration for effective transfer of power.