bluuebunny/crossref_metadata_2025 huggingface dataset:
Juvenile Systemic Sclerosis- A Case Report
Authors: Rahman ASMM , Uddin MB
Published: December 2018

Juvenile systemic sclerosis (JSS) is a multisystem disorder as well as rare disease of childhood, and the amount of published data is limited. It appears that its clinical presentation differs from adult disease and the limited form affects only very few children. The organ involvement pattern differs also from the adult form. Prognosis seems to be better with a 5-yr survival of 95% of the JSS patients. Though the incidence is very rare but we describe a 10-yr-old boy who presented with typical features of JSS.TAJ 2016; 29(2): 70-72
Result of Internal Fixation of Femoral Shaft Nonunion with Implant Failure by SIGN Interlocking Nail at Rajshahi Medical College Hospital
Authors: Hossain Mohd Alamgir , Shamima Mosammat Nargis , Iqbal Ahmed Asif , Haque Md Enamul , Parvez Md Qumruzzaman , Ahsanuzzaman Md
Published: December 2018

This prospective study on result of internal fixation of femoral shaft nonunion with implant failure by SIGN interlocking nail was carried out during the period of January 2009 to December 2016at Rajshahi Medical College Hospital, Bangladesh. Mean age of the patient was 34 years (11-70 years), majority of the patients were male (76%), injury was due to high energy trauma (88%), right side involvement was more (68%).Closed exchange nailing was done in 28 cases (56%) and open nailing was done in 22 cases (44%). In the open cases previous implants were removed, refreshening of the fracture ends was done. Antegrade or retrograde SIGN interlocking nailing depend on the site involvement. Reaming materials were used as internal bone graft in all the cases. Autogenouscancellous bone graft was given in 5 cases due to comminution at fracture site (2 cases) and severe osteoporosis (3 cases). The final outcome satisfactory result was found in 44 (88%) cases and unsatisfactory result in 6 (12%) cases.TAJ 2017; 30(1): 11-16
Marginal Resection of Sacral Chordoma through Posterior Approach: Study of 18 Cases
Authors: Islam Md Anowarul , Hossain Mohd Alamgir , Iqbal Ahmed Asif , Parvez Md Qumruzzaman , Rana Md Masud , Goni Fahad , Ahsanuzzaman Md
Published: December 2018

The study was carried out to report the results of marginal resection in sacral chordoma using a posterior midline approach. The study was carried out between July 2008 to June 2016, there were 21 patients who underwent the operation. Fourteen patients were male and seven were female and age ranging from 28 and 76 years. All most of the patients presented with pain, sacral mass and neurological deficit. Total sacrectomy and bone reconstruction were carried out in 11 patients. Subtotal sacrectomy was carried out in the remaining ten patients. Patients were followed up for at least seven years. Recovery after the operation was good. Duration of operation ranged between three to six hours. Three to five units blood was transfused in all patients after operation .Bowel and bladder dysfunction were almost all patients. After surgery following local complications including infection and wound disruption occurs in three patients and seroma occurs in two patients. Three patients (14%) had tumor recurrence and one patient expired three years after operation. 18 patients were still tumor-free at long term (seven years) follow-up. Marginal resection of sacral chordoma through posterior approachcan be a management plan for sacral chordoma with acceptable results.TAJ 2017; 30(1): 21-26
Myomectomy during Caesarean Section: A Safe Procedure
Authors: Akhtar Hasina , Chaudhury Shipra , Nahar Nazmun , Yusuf Nahid
Published: December 2018

Caesarean myomectomy which had traditionally discouraged in the past has recently been frequently employed to remove myoma at the time of caesarean section. If myomectomy during caesarean section become a wide spread practice, it could potentially be eliminate multiple surgeries for both indications. Objective of the study was to evaluate the safety and feasibility of performing myomectomy during caesarean section. Methods: This was a prospective study done in different private clinics in Rajshahi City from January 2012 to January 2015. Total 20 pregnant women with different sized fibroids were included in this study. Patients evaluated by age, parity, gestational age, difficulties during operation, blood loss during surgery, per and post-operative complications. Results: Blood loss during surgery was 750-1000 ml in 10 (50%) patients. Fifteen (75%) patients needed blood transfusion. The maternal morbidities like anaemia, pyrexia, and sepsis developed in 2(10%) of cases. There was no maternal or perinatal mortality. Conclusion: With the advent of better anesthesia and availability of blood, caesarean myomectomy is no longer a dreaded job in the hands of a skilled obstetrician in a well-equipped tertiary hospital.TAJ 2017; 30(1): 27-29
Successful Repair of Iatrogenic Cyclical Menouria
Authors: Shamima Mosammat Nargis , Zereen Rubayet , Begum Monwara , Akter Nurjahan , Khatun Mst Rowshan Ara , Kowsari Mosfika
Published: December 2018

Vesicouterine fistula (VUF) is a very rare occurrence and is estimated to occur in only (1-4%) of all genitourinary fistulas. It is an abnormal pathway between the bladder and the uterus. The most common cause is lower segment caesarean section. Patients usually present in the early post operative period with the problem of continuous urinary incontinence. On the rare occasion, recurrent urinary tract infection, recurrent gross painless haematuria, or secondary infertility associated with secondary amenorrhoea would be the presenting complaint. Among all vesicouterine fistula 90% are Youseef’s Syndrome the least common of the urogynaecological fistulas. Youseef’s syndrome is characterized by cyclic haematuria (menouria), absence of vaginal bleeding (amenorrhea) and urinary incontinence due to vesicouterine fistula (VUF).TAJ 2017; 30(1): 70-72
Dumb-Bell Shaped Hydatid Cyst in the Parotid Gland – A Rare Presentation
Authors: Ghosh Subrata , Chowdhury Milon Kumar , Haque Md Enamul , Haque Md Mahmudul , Ali Mahmud , Sarkar Subrata Ranjan , Islam Shafiul , Islam Akhterul , Islam Md Saiful
Published: December 2018

Human echinococcosis is a zoonotic infection caused by the tapeworm of the genus Echinococcus and transmitted by dog and other canine animals. It is a serious problem in tropical areas and is seen in many parts of Bangladesh. In children lungs are the most common site of infection, whereas in adults liver is infected most frequently. Primary hydatid cyst of the parotid gland is extremely rare, even in the endemic areas and very few cases are reported in parotid gland The disease is prevalent in most part of the world, though it is most extensive in the sheep and cattle raising areas. FNAC is contraindicated in suspected hydatid cyst cases due to risk of hypersensitivity reaction and additional precaution of intact cyst excision is mandatory in such cases to prevent recurrence and anaphylaxis reaction. A 30 year old female patient presented with gradually increasing painless large smooth cystic swelling of the right parotid region with trismus. CT scan showed a huge dumb bell shaped cystic lesion in the superficial and deep lobe of the parotid gland that is compatible with hydatid cyst. The parotid tumor was surgically removed by midline mandibulotomy approach. Pathological study of the cystic lesion confirmed hydatid disease of the parotid gland.TAJ 2017; 30(1): 73-77
Management and Outcome of Postoperative Complications among the Patients Undergoing Common Obstetric and Gynaecological Surgery outside the RMCH
Authors: Shamima Mosammat Nargis , Zereen Rubayet , Zahan Nargis , Khatun Most Rowshan Ara , Akter Nurjahan , Hossain Mohd Alamgir
Published: December 2018

Objective: To review the management and outcome of postoperative complications after common obstetric and gynecologic surgeries performed in outside nonacademic private hospitals (clinics) and peripheral public hospitals (districts hospitals) and later admitted in Department of Obstetrics and Gynecology of Rajshahi Medical College Hospital (RMCH). RMCH is a tertiary referral hospital where all complicated patients were referred for better management from surrounding hospital.Methodology: This Quasi-experimental study was carried out in the Department of Obstetrics and Gynecology at Rajshahi Medical College Hospital, Rajshahi, Bangladesh between July 1, 2015 and June 30, 2017. All patients admitted with post operative complications following common obstetric and gynecologic surgeries during this period were included. Patients admitted with post operative complications, where primary surgery was done in this hospital were excluded. The common obstetric and gynaecological surgeries were caesarean sections (LUCS), total abdominal hysterectomy (TAH) and vaginal hysterectomy (VH) performed outside Rajshahi Medical College Hospital.Result: During this period a total of 39,929 patients were admitted through emergency way in obstetrics and gynecology department of Rajshahi Medical College Hospital. Among them 675 patients were admitted with the complaints of post operative complications following common obstetric and gynecologic surgeries with rate being 1.7%. In 560(83%) cases surgery was done in clinics and 115(17%) cases surgery was done in district hospitals. Among the patients 580(85.9%) cases primary operation was done by non-gynaecologic surgeon and 95(14.1%) cases by gynaecologic surgeon. Caesarean section was the primary obstetric surgery in 405(60%) cases .Gynecologic surgeries included TAH in 185(27.4%) cases and VH in 85(12.6%) cases. We found 25(3.7%) patients died from these complications. Repeat surgery was done in 90(13.33%) cases. Genitourinary fistula repair was done in 41 cases (45.55%). Rests were improved by conservative management.Conclusion: Any surgical procedure carries risk of complications. Careful selection of patients with suitable indications for operations, expertise of the surgeon, good surgical technique, proper knowledge of pelvic anatomy and careful postoperative follow up can minimize recognized complications.TAJ 2017; 30(2): 7-12
A Comparative Study of the Effects of Lateral Wedge Insole Shoe Modification on the Patients with Knee Osteoarthritis
Authors: Khan Md Tariqul Islam , Ahmed Badrunnesa , Salek AKM , Karim Fazlul
Published: December 2018

Background: Knee osteoarthritis (OA) is the common form of disability in comparatively elderly patient. Lateral wedge shoe insole is an easy, simple and cost effective approach which can be applied as an adjunct to pharmacotherapy to treat the patients with OA knee. The objective of the study is to evaluate the effectiveness of using lateral wedge shoe insole on pain and physical functioning in patients with OA knee.Method: A randomized prospective study was carried out in the department of Physical Medicine and Rehabilitation, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh from January, 2012 to March, 2012. Patients with OA knee by American College of Rheumatology Criteria were selected. Two intervention groups were compared. In patients of Group-A (32 patients) were treated with aceclofenac100mg and, omeprazole20mg bid, and daily instructions of activities of daily living (ADLs), isometric quadriceps muscle strengthening exercise. Patients of Group-B were given lateral wedge shoe insole along with above treatment. The change between two weeks post intervention and baseline WOMAC (Western Ontario and McMaster Universities) subscale and scores were calculated. There were 4 visits and in each visit, patients were assessed for pain, stiffness and physical function by WOMAC index.Results: A total 65 patients with OA knee were included in this study. The mean age was 56.5± 10 years. Male to female ratio was 1.32:1. Comparison of mean pretreatment and 8th week post treatment WOMAC physical function subscale score in Group A (4.9 ± 1.2 vs. 2.4 ± 0.8) showed significant improvement and in Group B (4.3 ± 1.2 vs. 1.9 ± 0.5) which also shows significant improvement more than group A. The result was compared and student t-test was done to see the level of significance. Method was found significant after treatment (p <0.05).Interpretation: Effects of use of lateral wedge shoe insole in patients with knee OA is beneficial.TAJ 2017; 30(2): 13-19
Utility of Exfoliative Cytology of Voided Urine in Comparison with Ultrasonogram and Cystoscopy Findings in the Diagnosis of Urothelial Cancers
Authors: Badruddoza SM , Azim FA , Rahman AJE Nahar , Kamal M , Barua AR , Khan KH , Chowdhury T
Published: December 2018

Carcinoma of the urinary bladder affects men more often than women and occurs in patients over the age of 50 years. Transitional cell carcinoma (TCC) comprises about 90% of all primary tumor of urinary bladder. In this study a total of 57 cases were taken. The aim of the study was to establish diagnostic role of voided urine cytology, ultrasonography and cystoscopy in urothelial cancers. Out of 57 cases, cytological diagnosis was positive in 53 cases (93%) and negative in 4 cases (7%). There were no atypical or suspicious cases. Of the total cases, cytology was negative only in 7% cases. Among 42 invasive carcinomas 14 (33%) grade III invasive flat carcinoma, one (2%) invasive papillary adenocarcinoma and two (5%) invasive squamous cell carcinoma, each of them gave 100% positive cytology. Of the remaining 25 (60%) invasive papillary TCC, 21 were in grade II and 4 were in grade III. They gave 90% and 100% positive cytologic results. Ultrasonogram of urinary bladder gave 95% (approx.) positive results and out of 57 cases, 3 cases failed to give positive results in ultrasonogram (USG) of the urinary tract. Cystoscopy detected tumor mass in 98% cases and it gave false negative result in 2% cases. Fifty-two tumors had a diameter ranging 1.1- 6 cm. Single lesions were seen in 40 cases, double lesion in one case and multiple in 13 cases. The probability of later invasive carcinomas nearly tripled in-patients with multiple lesions on presentation (13.6%) compared with those who presented with a single lesion (4.6%). Consistent with previously published data, this study showed the highest diagnostic accuracy with high-grade tumors and lowest with low-grade tumors. So in a proper clinical setting, non-invasive technique like voided urine cytology and ultrasonography could be done as a first line cost effective method in the diagnosis of urothelial cancers.TAJ 2017; 30(2): 39-46
Effect of Aging on Glycemic Status during Pregnancy
Authors: Mahmuda Shahin , Akhtar Nasima , Sardar Mijanur Rahman , Asafudullah SM
Published: December 2018

Background: Pregnancy is associated with profound alteration in maternal metabolism. But this altered glucose homeostasis during pregnancy causes significant increase in feto-maternal abnormalities. This risk may increase due to maternal ageing.Objective: To assess the effect of ageing during pregnancy on fasting and postprandial glucose and glycated hemoglobin level in order to find out the risk of gestational diabetes.Methods: This cross sectional study was carried out in the department of Physiology, Rajshahi medical college, between the periods of January 2010 to December 2010. Three hundred pregnant woman aged 15 to 39 years were enrolled in the study and were divided into 5 different age groups, fasting and postprandial blood glucose and glycated hemoglobin levels were estimated by standard laboratory procedure. Data were analyzed by using SPSS computer software program and the test for significance was done by Chi-square test.Result: About 43% of pregnant women belonging to age group 35-39 years were detected as gestational diabetes mellitus, whereas less than 1% pregnant women among 20-24 years age group was detected as GDM. Blood sugar level both FBS and PPBS of all the pregnant women of age group 15-19 years are within normal limit.Conclusion: Results of the study indicates that the incidence of GDM was proportionate to increasing maternal age. So close monitoring of older pregnant women should be done to avoid feto-maternal complications.TAJ 2017; 30(2): 60-64
Interrupted Midline Fascial Closure to Prevent Burst Abdomen in Emergency Laparotomy: Comparison between Continuous and Interrupted closure
Authors: Islam Baharul , Islam Saiful , Roy Subroto Kumar , Alam Nur Kutubul , Rahman Tahmidur , Sarkar Md Habibullah
Published: December 2018

Burst abdomen represents one of the most frustrating and difficult postoperative complication that concerns every abdominal surgeon. It occurs because of various predisposing factors which can be prevented to some extend by having knowledge regarding them. Despite many years of experience, the optimal technique of laparotomy closure remains controversial. The varieties of surgical excess as well as the varieties of abdominal closure techniques are the main difficulties in the proper standardization of this procedure. In this paper a randomized prospective study was designed to compare with a interrupted and continuous technique for closing a midline abdominal fascia in emergency laparotomy. A total of 300 patients of acute abdominal condition who underwent laparotomy were randomized into two groups of 150 patients in each group. Total 22(7.33%) of 300 patients developed burst in the postoperative period. Fourteen (14) (9.33%) in continuous arms and eight (08) (5.33%) patients in interrupted arms developed burst. Burst abdomen occurring mostly 40-60 years age group with a male to female ratio of 1.68: 1. Cough, anemia, malnutrition, DM, intraperitoneal sepsis, wound infection, uremia and abdominal distension were the important predisposing factors for the incidence of burst abdomen. Interrupted suturing was associated with significantly reduced the burst abdomen when comparing with continuous closure.TAJ 2017; 30(2): 69-75
Gear and Runge–Kutta Numerical Discretization Methods in Differential Equations of Adsorption in Adsorption Heat Pump
Authors: Zwarycz-Makles Katarzyna , Majorkowska-Mech Dorota
Published: December 2018

The main aim of this paper was to find the correct method of calculating equations of heat and mass transfer for the adsorption process and to calculate it numerically in reasonable time and with proper accuracy. An adsorption heat pump with a silica gel adsorbent and water adsorbate is discussed. We developed a mathematical model of temperature and uptake changes in the adsorber/desorber comprising the set of heat and mass balance partial differential equations (PDEs), together with the initial and boundary conditions and solved it by the numerical method of lines (NMOL). Spatial discretization was performed with equally spaced axial nodes and the PDEs were reduced to a set of ordinary differential equations (ODEs). We focused on the comparison of results obtained when the set of heat and mass balance ODEs for an adsorber was solved using: (1) the Runge–Kutta fixed step size fourth-order method (RKfixed), (2) the Runge–Kutta–Fehlberg 4.5th-order method with a variable step size (RK45), and (3) the Gear Backward Differentiation Formulae numerical (Gear BDF) methods. In our experience, all three types of ODE numerical methods (RKfixed, RK45, and Gear BDF) can be applied in simple models to model an adsorber with attention on their limitations. The Gear BDF method usually requires much fewer steps than the RK45 method for almost the same calculating time. RK methods require many more steps to obtain results, and the calculating time depends on accuracy or defined time step. Moreover, one should pay attention to the number of nodes or possible oscillations.
Investigating the Linkage between Economic Growth, Electricity Access, Energy Use, and Population Growth in Pakistan
Authors: Rehman Abdul , Deyuan Zhang
Published: December 2018

Electricity is a versatile form of energy that plays a vital role in fulfilling the daily requirements of human life. The primary aim of this study was to investigate and explore the link between economic growth, electricity access, energy use, and population growth in Pakistan for the period 1990–2016. An autoregressive distributed lag (ARDL) bounds testing approach to cointegration was applied to investigate the causality link between the study variables. These tests shed light on the long-run connection among the variables; further, the results revealed that the electricity access to the total population, electricity access to the urban population, energy usage, population growth, and urban population growth had a significant impact on economic growth, while the electricity access to the rural population and rural population growth had a negative impact on the economic growth in Pakistan. According to these findings, this study recommends that the government of Pakistan pay further attention to increasing its electricity production from different sources, including hydroelectric, solar, oil, and gas, and nuclear in order to fulfill the country’s demands.
Dynamics of Fe, Mn, and Al Liberated from Contaminated Soil by Low-Molecular-Weight Organic Acids and Their Effects on the Release of Soil-Borne Trace Elements
Authors: Qin Junhao , Enya Osim , Lin Chuxia
Published: December 2018

A 15-day batch experiment was conducted to investigate the behaviours of Fe, Mn, and Al oxides upon attack by three common low-molecular-weight organic acids, and their effects on liberation of trace elements from a multi-contaminated soil. While the capacity of malic acid to mobilize soil-borne Fe, Mn, and Al was weaker compared to citric and oxalic acids, a similar trend was observed, showing that the concentration of dissolved Fe, Mn, and Al increased with increasing duration of the experiment. Marked increase in metal concentrations only took place after 5 or 7 days of the experiment. For the same organic acid treatment, Fe, Mn, and Al all showed a very similar temporal variation pattern. The concentration of dissolved Fe, Mn, and Al was markedly controlled by the total Fe, Mn, and Al contained in the soil, respectively. It appears that manganese oxides were more reactive to the organic acids, as compared to their Fe and Al counterparts. However, when multiple organic acids were present, the soil-borne Fe, Mn, and Al were mobilized rapidly within the first 5 or 7 days of the experiment and then tended to decrease. The formation of insoluble Fe, Mn, and Al organic complexes tended to be enhanced due to co-existence of multiple organic acids, resulting in the re-immobilization of the dissolved Fe, Mn, and Al. The organic acid-driven dissolution of Fe, Mn, or Al had a major control on the mobilization of As, Cr, Zn, Ni, Cu, and Cd that were bound to these oxides with a correlation coefficient being frequently greater than 0.9 for As, Cr, Zn, and Ni.
Image Segmentation Approaches for Weld Pool Monitoring during Robotic Arc Welding
Authors: Wang Zhenzhou , Zhang Cunshan , Pan Zhen , Wang Zihao , Liu Lina , Qi Xiaomei , Mao Shuai , Pan Jinfeng
Published: December 2018

There is a strong correlation between the geometry of the weld pool surface and the degree of penetration in arc welding. To measure the geometry of the weld pool surface robustly, many structured light laser line based monitoring systems have been proposed in recent years. The geometry of the specular weld pool could be computed from the reflected laser lines based on different principles. The prerequisite of accurate computation of the weld pool surface is to segment the reflected laser lines robustly and efficiently. To find the most effective segmentation solutions for the images captured with different welding parameters, different image processing algorithms are combined to form eight approaches and these approaches are compared both qualitatively and quantitatively in this paper. In particular, the gradient detection filter, the difference method and the GLCM (grey level co-occurrence matrix) are used to remove the uneven background. The spline fitting enhancement method is used to remove the fuzziness. The slope difference distribution-based threshold selection method is used to segment the laser lines from the background. Both qualitative and quantitative experiments are conducted to evaluate the accuracy and the efficiency of the proposed approaches extensively.
Towards GW-Scale Isolated Attosecond Pulse Far beyond Carbon K-Edge Driven by Mid-Infrared Waveform Synthesizer
Authors: Fu Yuxi , Yuan Hua , Midorikawa Katsumi , Lan Pengfei , Takahashi Eiji J.
Published: December 2018

We discuss the efficient generation of intense “water window” (0.28–0.54 keV) isolated attosecond pulses (IAPs) using a mid-infrared (MIR) waveform synthesizer. Our numerical simulations clearly indicate that not only a longer-wavelength driving laser but also a weak control pulse in the waveform synthesizer helps extend the continuum cutoff region and reduce the temporal chirp of IAPs in high-order harmonic generation (HHG). This insight indicates that a single-cycle laser field is not an optimum waveform for generating the shortest IAP from the veiwpoints of reducing the attochirp and increasing the efficiency of HHG. By combining a waveform synthesizer technology and a 100 mJ MIR femtosecond pulse based on a dual-chirped optical parametric amplification (DC-OPA) method, a gigawatt-scale IAP (55 as with 10 nJ order) in the water window region can be generated even without attochirp compensation. The MIR waveform synthesizer is highly beneficial for generating a shorter IAP duration in the soft X-ray region because there are no suitable transparent dispersive materials that can be used for compressing the attochirp.
Study on Elastic Global Shear Buckling of Curved Girders with Corrugated Steel Webs: Theoretical Analysis and FE Modelling
Authors: Wang Kangjian , Zhou Man , Hassanein Mostafa , Zhong Jitao , Ding Hanshan , An Lin
Published: December 2018

Despite the construction of several curved prestressed concrete girder bridges with corrugated steel webs (CSWs) around the world; their shear behavior has seldom been investigated. Accordingly, this paper substitutes the lack of available information on the global elastic shear buckling of a plane curved corrugated steel web (PCCSW) in a curved girder. This is based on the equilibrium equations and geometric equations in the elastic theory of classical shells, combined with the constitutive relation of orthotropic shells. Currently, the global elastic shear buckling process of the PCCSW in a curved girder is studied, for the first time in literature, with an equivalent orthotropic open circular cylindrical shell (OOCCS) model. The governing differential equation of global elastic shear buckling of the PCCSW, as well as its buckling strength, is derived by considering the orthotropic characteristics of a corrugated steel web, the rational trigonometric displacement modes, Galerkin’s method and variational principles. Additionally, the accuracy of the proposed theoretical formula is verified by comparison with finite element (FE) results. Moreover, the expressions of the inner or outer folded angle and radius of curvature are given by the cosine theorem of the trigonometric function and inverse trigonometric function. Subsequently, parametric analysis of the shear buckling behavior of the PCCSW is carried out by considering the cases where the radius of curvature is constant or variable. This parametric analysis highlights the effects of web dimensions, height-to-thickness ratio, aspect ratios of longitudinal and inclined panels, corrugation height, curvature radius and folded angles on the elastic shear buckling strength. As a result, this study provides a theoretical reference for the design and application of composite curved girders with CSWs.
Improvement of Mechanical Performance of Bioresorbable Magnesium Alloy Coronary Artery Stents through Stent Pattern Redesign
Authors: Wang Qian , Fang Gang , Zhao Ying-Hong , Zhou Jie
Published: December 2018

Optimized stent pattern design can effectively enhance the mechanical performance of magnesium alloy stents by adjusting strain distribution and evolution during stent deformation, thereby overcoming the limitations imposed by the intrinsic mechanical properties of magnesium alloys. In the present study, a new stent design pattern for magnesium alloys was proposed and compared to two existing stent design patterns. Measures of the mechanical performance of these three stents, including crimping and expanding deformability, radial scaffolding capacity, radial recoil and bending flexibility, were determined. Three-dimensional finite element (FE) models were built to predict the mechanical performance of the stents with the three design patterns and to assist in understanding the experimental results. The results showed that, overall, the stent with the new design pattern was superior to the stents based on the existing designs, though the expanding capacity of the newly designed stent still needed to be improved.
Study on the Decomposition Mechanism of Natural Gas Hydrate Particles and Its Microscopic Agglomeration Characteristics
Authors: Lv Xiaofang , Shi Bohui , Zhou Shidong , Wang Shuli , Huang Weiqiu , Sun Xianhang
Published: December 2018

Research on hydrate dissociation mechanisms is critical to solving the issue of hydrate blockage and developing hydrate slurry transportation technology. Thus, in this paper, natural gas hydrate slurry decomposition experiments were investigated on a high-pressure hydrate experimental loop, which was equipped with two on-line particle analyzers: focused beam reflectance measurement (FBRM) and particle video microscope (PVM). First, it was observed from the PVM that different hydrate particles did not dissociate at the same time in the system, which indicated that the probability of hydrate particle dissociation depended on the particle’s shape and size. Meanwhile, data from FBRM presented a periodic oscillating trend of the particle/droplet numbers and chord length during the hydrate slurry dissociation, which further demonstrated these micro hydrate particles/droplets were in a dynamic coupling process of breakage and agglomeration under the action of flow shear during the hydrate slurry dissociation. Then, the influences of flow rate, pressure, water-cut, and additive dosage on the particles chord length distribution during the hydrate decomposition were summarized. Moreover, two kinds of particle chord length treatment methods (the average un-weighted and squared-weighted) were utilized to analyze these data onto hydrate particles’ chord length distribution. Finally, based on the above experimental data analysis, some important conclusions were obtained. The agglomeration of particles/droplets was easier under low flow rate during hydrate slurry dissociation, while high flow rate could restrain agglomeration effectively. The particle/droplet agglomerating trend and plug probability went up with the water-cut in the process of hydrate slurry decomposition. In addition, anti-agglomerates (AA) greatly prohibited those micro-particles/droplets from agglomeration during decomposition, resulting in relatively stable mean and square weighting chord length curves.
First-Principles Investigation of Atomic Hydrogen Adsorption and Diffusion on/into Mo-doped Nb (100) Surface
Authors: Wu Yang , Wang Zhongmin , Wang Dianhui , Qin Jiayao , Wan Zhenzhen , Zhong Yan , Hu Chaohao , Zhou Huaiying
Published: December 2018

To investigate Mo doping effects on the hydrogen permeation performance of Nb membranes, we study the most likely process of atomic hydrogen adsorption and diffusion on/into Mo-doped Nb (100) surface/subsurface (in the Nb12Mo4 case) via first-principles calculations. Our results reveal that the (100) surface is the most stable Mo-doped Nb surface with the smallest surface energy (2.75 J/m2). Hollow sites (HSs) in the Mo-doped Nb (100) surface are H-adsorption-favorable mainly due to their large adsorption energy (−4.27 eV), and the H-diffusion path should preferentially be HS→TIS (tetrahedral interstitial site) over HS→OIS (octahedral interstitial site) because of the correspondingly lower H-diffusion energy barrier. With respect to a pure Nb (100) surface, the Mo-doped Nb (100) surface has a smaller energy barrier along the HS→TIS pathway (0.31 eV).
Convolution Neural Network with Selective Multi-Stage Feature Fusion: Case Study on Vehicle Rear Detection
Authors: Lee Won-Jae , Kim Dong W. , Kang Tae-Koo , Lim Myo-Taeg
Published: December 2018

Vision-based vehicle detection is the most basic and important technology in advanced driver assistance systems. In this paper, we propose a vehicle detection framework using selective multi-stage features in convolutional neural networks (CNNs) to improve vehicle detection performance. A 10-layer CNN model was designed and visualization techniques were used to selectively extract features from the activation feature map, called selective multi-stage features. The proposed features contain characteristic vehicle image information and are more robust than traditional features against noise. We trained the AdaBoost algorithm using these features to implement a vehicle detector. The experimental results verified that the proposed vehicle detection framework exhibited better performance than previous frameworks.
Impact of Atmospheric Circulation on the Occurrence of Hot Nights in Central Europe
Authors: Tomczyk Arkadiusz Marek
Published: December 2018

The main goal of the study is to determine the pressure conditions that cause waves of hot nights in Central Europe. The goal was implemented on the basis of data from 1966 to 2015, made available by the Institute of Meteorology and Water Management—National Research Institute, Deutscher Wetterdienst and the National Center for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR). A hot night was defined as a day with the minimum air temperature above 18 °C. In the analysed years, an increase in the number of hot nights was found, which was predominantly statistically significant within the studied area. The study shows that the occurrence of waves of hot nights in Central Europe was associated on average with the ridge of high pressure, within which a local high-pressure area developed. During the waves of hot nights, there were positive anomalies of heights of isobaric surfaces over the study area with a maximum in the upper troposphere.
Chiral Plasmonic Biosensors
Authors: Bochenkov Vladimir E. , Shabatina Tatyana I.
Published: December 2018

Biosensing requires fast, selective, and highly sensitive real-time detection of biomolecules using efficient simple-to-use techniques. Due to a unique capability to focus light at nanoscale, plasmonic nanostructures provide an excellent platform for label-free detection of molecular adsorption by sensing tiny changes in the local refractive index or by enhancing the light-induced processes in adjacent biomolecules. This review discusses the opportunities provided by surface plasmon resonance in probing the chirality of biomolecules as well as their conformations and orientations. Various types of chiral plasmonic nanostructures and the most recent developments in the field of chiral plasmonics related to biosensing are considered.
Non-Invasive Diagnosis of Diabetes by Volatile Organic Compounds in Urine Using FAIMS and Fox4000 Electronic Nose
Authors: Esfahani Siavash , Wicaksono Alfian , Mozdiak Ella , Arasaradnam Ramesh P. , Covington James A.
Published: December 2018

The electronic nose (eNose) is an instrument designed to mimic the human olfactory system. Usage of eNose in medical applications is more popular than ever, due to its low costs and non-invasive nature. The eNose sniffs the gases and vapours that emanate from human waste (urine, breath, and stool) for the diagnosis of variety of diseases. Diabetes mellitus type 2 (DM2) affects 8.3% of adults in the world, with 43% being underdiagnosed, resulting in 4.9 million deaths per year. In this study, we investigated the potential of urinary volatile organic compounds (VOCs) as novel non-invasive diagnostic biomarker for diabetes. In addition, we investigated the influence of sample age on the diagnostic accuracy of urinary VOCs. We analysed 140 urine samples (73 DM2, 67 healthy) with Field-Asymmetric Ion Mobility Spectrometry (FAIMS); a type of eNose; and FOX 4000 (AlphaM.O.S, Toulouse, France). Urine samples were collected at UHCW NHS Trust clinics over 4 years and stored at −80 °C within two hours of collection. Four different classifiers were used for classification, specifically Sparse Logistic Regression, Random Forest, Gaussian Process, and Support Vector on both FAIMS and FOX4000. Both eNoses showed their capability of diagnosing DM2 from controls and the effect of sample age on the discrimination. FAIMS samples were analysed for all samples aged 0–4 years (AUC: 88%, sensitivity: 87%, specificity: 82%) and then sub group samples aged less than a year (AUC (Area Under the Curve): 94%, Sensitivity: 92%, specificity: 100%). FOX4000 samples were analysed for all samples aged 0–4 years (AUC: 85%, sensitivity: 77%, specificity: 85%) and a sub group samples aged less than 18 months: (AUC: 94%, sensitivity: 90%, specificity: 89%). We demonstrated that FAIMS and FOX 4000 eNoses can discriminate DM2 from controls using urinary VOCs. In addition, we showed that urine sample age affects discriminative accuracy.
Reduced Graphene Oxide/TiO2 Nanocomposite: From Synthesis to Characterization for Efficient Visible Light Photocatalytic Applications
Authors: Rommozzi Elena , Zannotti Marco , Giovannetti Rita , D’Amato Chiara Anna , Ferraro Stefano , Minicucci Marco , Gunnella Roberto , Di Cicco Andrea
Published: December 2018

In this study, a green and facile thermal reduction of graphene oxide using an eco-friendly system of d-(+)-glucose and NH4OH for the preparation of reduced graphene oxide was described. The obtained reduced graphene oxide dispersion was characterized by SEM, Dynamic Light Scattering, Raman and X-Ray Photoelectron Spectroscopy. TiO2 nanoparticles and reduced graphene oxide nanocomposites were successively prepared and used in the preparation of heterogeneous photocatalysts that were characterized by Atomic Force Microscopy and Photoluminescence Spectroscopy and subsequently tested as visible light photocatalysts for the photodegradation of Alizarin Red S in water as target pollutant. Obtained results of photocatalytic tests regarding the visible light photocatalytic degradation of Alizarin Red S demonstrated that the use of reduced graphene oxide in combination with TiO2 led to a significant improvement for both adsorption of Alizarin Red S on the catalyst surface and photodegradation efficiencies when compared to those obtained with not doped TiO2.
BF3·Et2O-Promoted Decomposition of Cyclic α-Diazo-β-Hydroxy Ketones: Novel Insights into Mechanistic Aspects
Authors: Venturoni Francesco , Cerra Bruno , Marinozzi Maura , Camaioni Emidio , Gioiello Antimo , Pellicciari Roberto
Published: December 2018

We report novel insights into the cascade rearrangement of destabilized vinyl cations deriving from the BF3·Et2O-induced decomposition of cyclic α-diazo-β-hydroxy ketones in turn prepared by aldol-type condensation of cycloalkanones with diazoacetone. Complexation of the hydroxy group of the α-diazo-β-hydroxy compound with the Lewis acid is the first event, followed by the generation of the cycloalkanylidenediazonium salt that, after nitrogen loss, produces the highly reactive vinyl cation. The subsequent ring expansion results in the formation of a cycloalkenyl vinyl cation that affords the allylic cation by 1,2-methylene shift and ring contraction. The cation can then trap the solvent, the fluoride or the hydroxide released from the [BF3OH]− to afford different reaction products. The effect of both solvent and substrate ring size on products types and ratios were analyzed and discussed from a mechanistic point of view.
Switchable Intrinsic Defect Chemistry of Titania for Catalytic Applications
Authors: Jayashree Swaminathan , Ashokkumar Meiyazhagan
Published: December 2018

The energy crisis is one of the most serious issue that we confront today. Among different strategies to gain access to reliable fuel, the production of hydrogen fuel through the water-splitting reaction has emerged as the most viable alternative. Specifically, the studies on defect-rich TiO2 materials have been proved that it can perform as an efficient catalyst for electrocatalytic and photocatalytic water-splitting reactions. In this invited review, we have included a general and critical discussion on the background of titanium sub-oxides structure, defect chemistries and the consequent disorder arising in defect-rich Titania and their applications towards water-splitting reactions. We have particularly emphasized the origin of the catalytic activity in Titania-based material and its effects on the structural, optical and electronic behavior. This review article also summarizes studies on challenging issues on defect-rich Titania and new possible directions for the development of an efficient catalyst with improved catalytic performance.
Acetylene Abatement Over Micro/Mesoporous Active Carbon-Supported Low-Mercury Catalysts
Authors: Jiang Luo , Liu Ning , Dai Chengna , Xu Ruinian , Chen Biaohua , Zhang Jirui
Published: December 2018

A series of low HgCl2-supported catalysts (K-TX-O, K-WG-O, K-S20-O, K-S40-O, K-Fe0.8-O, K-Fe0.8-M, D-Fe0.8-M) was prepared and investigated for C2H2 catalytic abatement during highly purified HCl (HP-HCl) production process. The samples of D-Fe0.8-M, K-Fe0.8-M, and K-Fe0.8-O were found to exhibit much higher activities and better thermal stabilities than those of other samples. The characterization results of XRD, N2 adsorption/desorption, SEM, back scattered electron (BSE) and thermogravimetry (TG) revealed that: (i) the larger mesoporous volumes constituted one of the key factors leading to superior catalytic performances of D-Fe0.8-M, K-Fe0.8-M, and K-Fe0.8-O, which greatly facilitated better dispersions of the loaded HgCl2 species in comparison to other samples; (ii) the KCl additive could further improve the dispersions and thermal stabilities of the loaded the HgCl2 species due to the strong interactions between KCl and HgCl2 species, resulting in relatively higher catalytic behaviors of D-Fe0.8-M and K-Fe0.8-M than that of K-Fe0.8-O; (iii) the KCl/HgCl2 step-by-step loading strategy, wherein the KCl was initially loaded on the Fe0.8-AC substrate thereafter followed by HgCl2 loading, could further improve the catalytic behavior for D-Fe0.8-M due to additional improvements of HgCl2 dispersions. The deactivation and reactivation of D-Fe0.8-M during HP-HCl were also investigated, which suggested that partial deactivated D-Fe0.8-M by C2H3Cl accumulation could be efficiently reactivated by HCl treatment at T = 220 °C.
Preparation of Innovative Skin Compatible Films to Release Polysaccharides for Biobased Beauty Masks
Authors: Coltelli Maria-Beatrice , Danti Serena , Trombi Luisa , Morganti Pierfrancesco , Donnarumma Giovanna , Baroni Adone , Fusco Alessandra , Lazzeri Andrea
Published: December 2018

The preparation and selection of biobased materials compatible with skin is essential for producing innovative and highly eco-friendly beauty masks. The use of a commercial elastomeric poly(hydroxyalkanoate) and starch was fundamental to select materials for bioplastic films with the necessary resistance in wet conditions, skin compatibility and capacity for a fast release of polysaccharides and similar active and functional molecules. Micrometric calcium carbonate was also used to control the stickiness of film during moulding. Starch release in water was investigated by gravimetric and infrared analyses. The compatibility with skin was investigated via two different in vitro tests based on human keratinocytes and human mesenchymal stromal cells. The materials were highly cytocompatible with skin, enabled immune modulation by keratinocytes and starch release in water up to 49% by weight in 30 min. These outcomes are a good starting point for boosting the production of biobased and biodegradable beauty masks, thus decreasing the impact onto environment of cosmetic products that are currently still mainly produced using petrol-based substrates.
Television Rating Control in the Multichannel Environment Using Trend Fuzzy Knowledge Bases and Monitoring Results
Authors: Azarov Olexiy , Krupelnitsky Leonid , Rakytyanska Hanna
Published: December 2018

The purpose of this study is to control the ratio of programs of different genres when forming the broadcast grid in order to increase and maintain the rating of a channel. In the multichannel environment, television rating controls consist of selecting content, the ratings of which are completely restored after advertising. The hybrid approach to rule set refinement based on fuzzy relational calculus simplifies the process of expert recommendation systems construction. By analogy with the problem of the inverted pendulum control, the managerial actions aim to retain the balance between the fuzzy demand and supply. The increase or decrease trends of the demand and supply are described by primary fuzzy relations. The rule-based solutions of fuzzy relational equations connect significance measures of the primary fuzzy terms. Program set refinement by solving fuzzy relational equations allows avoiding procedures of content-based selective filtering. The solution set generation corresponds to the granulation of television time, where each solution represents the time slot and the granulated rating of the content. In automated media planning, generation of the weekly TV program in the form of the granular solution provides the decrease of time needed for the programming of the channel broadcast grid.
Multirotor Drone Aerodynamic Interaction Investigation
Authors: Shukla Dhwanil , Komerath Narayanan
Published: December 2018

Aerodynamic interactions between rotors are important factors affecting the performance of in-plane multirotor Unmanned Air Vehicles (UAVs) or drones, which are the majority of small size UAVs (or mini-drones). Optimal design requires knowledge of the flow features. The low Reynolds number of many UAV rotors raises the question of how these features differ from those expected by traditional analytical methods for rotorcraft. Aerodynamics of a set of side-by-side rotors in hover over a range of rotor separation and Reynolds number is studied using high-speed Stereo Particle Image Velocimetry (SPIV) and performance measurements. The instantaneous and time-averaged SPIV data presented here indicate an increase in inter-rotor wake interactions with decrease in rotor spacing and Reynolds number. A dip in rotor efficiency at small rotor spacing at low Reynolds number is observed through thrust and torque measurements. The basic components of in-plane multirotor wake and velocity profiles are identified and discussed to help generalize the findings to a wide range of drones. However, the data provide confidence in traditional analysis tools, with small modifications.
Experimental Evaluation of Multipath Mitigation in TDOA-Based Indoor Passive Localization System Using A Beam Steering Broadband Circular Polarization Antenna
Authors: Su Changjiang , Liu Yanqun , Liu Leilei , Yang Mei , Zhao Hongxin , Yin Xiaoxing
Published: December 2018

An experimental evaluation of multipath mitigation using a beam steering broadband circular polarization antenna (BSBCPA) in indoor passive localization system based on time differences of arrival (TDOA) is presented in this paper. The BSBCPA consists of a beam switch network, four identical hexagon patch elements and their respective feeding networks. By controlling the states of a radio frequency (RF) switch in the beam switch network, four steering circular polarization beams can be excited separately for azimuth omnidirectional coverage. Combining the spatial selectivity of steering beams and circular polarization in the BSBCPA, the positioning inaccuracy from indoor multipath propagation can be mitigated. In two different indoor environments with line of sight (LOS), complex multipath, when transmitting a 20 MHz bandwidth signal in WLAN, the 2D positioning mean error obtained is 0.7 m and 0.82 m, respectively. Compared with conventional omnidirectional linear polarization antenna (OLPA), the BSBCPA can at least improve positioning accuracy by 51%. The experimental results show that the proposed BSBCPA can significantly mitigate multipath propagation for TDOA-based indoor passive localization.