bluuebunny/crossref_metadata_2025 huggingface dataset:
Multicriteria Model to Support Governance in Electoral Institutions
Authors: Martins Sérgio Manoel , Ensslin Leonardo , Dutra Ademar , Ensslin Sandra Rolin
Published: September 2020

In democracies, power is exercised through political representation and is expressed in periodic elections. In recent decades, the population's heightened commitment to morality and the way public policies have been conducted have provoked demands from society for stricter controls and transparency in the actions of electoral institutions worldwide. In this context, considering the relevance of the performance of these institutions for legitimacy in elections and political stability, this study presents a process to support governance and election legitimacy management. The constructivist multicriteria methodology guided the construction of the model by identifying strategic objectives and highlighting properties associated with critical factors, which allowed for the measurement of performance and the identification of competitive differentials and vulnerabilities. The process of support for governance has the potential to boost performance, increase the credibility of electoral institutions, and increase society's confidence in elections.
A Comparative Analysis of CE-Topsis and CE-Maut Methods
Authors: Altin Hakan
Published: September 2020

The key objective of this study is to conduct a comparative analysis of performance ranking results of the two multi-criteria decision-making methods, namely TOPSIS and MAUT. In this study, the CRITIC and ENTROPY methods were utilized as objective weighting techniques. In the application part of this study, three salient findings were attained. The first finding was that of the close relationship between TOPSIS ranking conducted by CRITIC and ENTROPY methods. The second finding was that of the close relationship between the MAUT ranking conducted by the CRITIC and ENTROPY methods. The third finding was that of the mutual and significant relationship in a positive direction between the performance ranking results obtained by TOPSIS and MAUT methods. In other words, TOPSIS and MAUT methods give the same performance ranking results. The results found are statistically significant.
A Probabilistic Multi-Objective Approach for Power Flow Optimization in Hybrid Wind-Based Power Systems Using Grasshopper Optimization Algorithm
Authors: Mandal Barun , Roy Provas Kumar
Published: September 2020

This article introduces a grasshopper optimization algorithm (GOA) to efficiently prove its superiority for solving different objectives of optimal power flow (OPF) based on a mixture thermal power plant that incorporates uncertain wind energy (WE) sources. Many practical constraints of generators, valve point effect, multiple fuels, and the various scenarios incorporating several configurations of WEs are considered for both singles along with multi-objectives for the OPF issue. Within the article, the considered method is verified on two common bus experiment systems, i.e. IEEE 30-bus as well as the IEEE 57-bus. Here, the fuel amount minimization and emission minimization are studied as the primary purposes of a GOA-based OPF problem. However, the proposed algorithm yields a reasonable conclusion about the better performance of the wind turbine. Computational results express the effectiveness of the proposed GOA approach for the secure and financially viable of the power system under various uncertainties. The comparison is tabulated with the existing algorithms to provide superior results.
Modified Moth-Flame Optimization Algorithm-Based Multilevel Minimum Cross Entropy Thresholding for Image Segmentation
Authors: Khairuzzaman Abdul Kayom Md , Chaudhury Saurabh
Published: September 2020

Multilevel thresholding is a widely used image segmentation technique. However, multilevel thresholding becomes more and more computationally expensive as the number of thresholds increase. Therefore, it is essential to incorporate some suitable optimization technique to make it practical. In this article, a modification is proposed to the Moth-Flame Optimization (MFO) algorithm and then it is applied to multilevel thresholding for image segmentation. Cross entropy is used as the objective function to select the optimal thresholds. A set of benchmark test images are used to evaluate the proposed technique. The Mean Structural SIMilarity (MSSIM) index is used to measure the quality of the segmented images. The results of the proposed technique are compared with the original MFO, PSO, BFO, and WOA. Experimental results and analysis suggest that the proposed technique outperforms other techniques in terms of segmentation quality images and stability. Moreover, computation time required for multilevel thresholding is also reduced to a manageable level.
Study on Preparation of Microstructured Optical Membrane
Authors: Zhao Chang Song , Wu Jun Yong , Chu Fan Zhong , Zhao Kai Rui , Yu Lei
Published: September 2020

Micro-structured optical film is one of the micro-optical elements and has a great market demand. This article studies the microstructured optical film formed by UV imprinting: The influence of embossing pressure on microstructure replication accuracy was explored. The larger the pressure, the better the material filling. When the pressure is 5N, the microstructure replication is complete; The relationship between the radiation intensity and warpage deformation was explored, and the decrease in the intensity of the UV light source can effectively reduce the warpage deformation; The influence of the material formula on the optical properties of the product was explored. When the oligomer content was 55%, the film had a high light transmittance. At the same time, the prepared film was subjected to an apparent inspection with good microstructure replication accuracy.Microstructured optical elements are widely used in optical fields such as semiconductors, lasers, beam shaping [1-2] and solar energy [3-5] due to their unique advantages such as small size and high performance. As a key component in many industries, it has a high market demand rate. However, the microstructure forming process is complicated, the manufacturing cost is high, and the accuracy is difficult to guarantee, which has restricted its development. With the advancement of science and technology and the increase in market demand, more and more researchers and enterprises have put their eyes on the research of preparing micro-structured optical elements.At present, the commonly used microstructures are mainly icrolens array [6-8], and the processing methods include micro-imprinting [9-10], etching [11], electron beam direct writing, and micro-injection [12], etc. This article studies the UV-curing embossing process in micro-embossing. This processing method has the advantages of fast molding, high efficiency, and environmental protection. And this process is conducive to mass production and has a broad market application prospect.In this paper, the forming process and material formulation of microstructured optical film prepared by light-cured micro-imprinting were investigated, and the microstructure morphology of the preparation was analyzed apparently.
Underwater Laser Turning of Commercially-Pure Titanium
Authors: Charee Wisan , Tangwarodomnukun Viboon
Published: September 2020

Underwater laser machining process is a material removal technique that can minimize thermal damage and offer a higher machining rate than the laser ablation in ambient air. This study applied the underwater method associated with a nanosecond pulse laser for turning a commercially pure titanium rod. The effects of laser power, surface speed and number of laser passes on machined depth and surface roughness were investigated in this work. The results revealed that a deeper cut depth and smoother machined surface than those obtained from the laser ablation in ambient air were achievable when the underwater laser turning process was applied. The machined depth and surface roughness were found to significantly increase with the laser power and number of laser passes. The findings of this study can disclose the insight as well as potential of the underwater laser turning process for titanium and other similar metals.
The Sintering Process and Mechanism of YAG Pore Gradient Ceramics
Authors: Liu Yue , Chen Lin , Song Jie Guang , Luo Hui Hui , Wei Chen Hui , He Chun Yan , Sun Jia Min , Guan Zhi Qiang
Published: September 2020

Yttrium aluminum garnet is abbreviated as YAG, which has many excellent high temperature characteristics. YAG structural materials and functional materials are promising candidates. In this paper, YAG porous ceramic materials with different mechanical properties are prepared by adjusting the parameters of the sintering process to provide reference for the preparation of high-performance porous ceramics. From the experimental results, the following conclusions can be drawn: when the sintering temperature is 1450°C and the holding time is 2h, the YAG gradient porous ceramics have no deformation and shrinkage, have a regular good shape, and have good strength after sintering. The sintering rate was 8 °C/min and carbon emission temperature is 800°C, the structure of the YAG gradient porous material is good, the pores are uniform, and the strength of the sintered sample is high, The porosity is 25.7%, the compressive strength is 8.12MPa.
Preparation and Characterization of Coated Alumina/Aluminum Cermet Composite Powder via Ball Milling Method
Authors: Wang Fang , Chen Ai Xia , Yang Chao , Xu Min Han , Du Da Ming , Luo Hui Hui , He Chun Yan , Song Jie Guang
Published: September 2020

Cermet is an important new engineering material that not only maintains the excellent properties of ceramic materials, but also has the advantages of metal materials. In this paper, the encapsulated alumina-aluminum composite powder was prepared by ball milling and characterized, which laid a foundation for the development of high properties cermet materials. Through the analysis of experimental results, the conclusions are shown when the ball milling time is greater than 3 h, the alumina particles are more evenly distributed around the aluminum powder. the ball milling for 6 h may have reached a limit of the mixing uniformity of the two powder, so the ball milling is determined 6 h as the better ball milling time. Under the ball milling condition of 50 r/min, the distribution of alumina particles around the aluminum powder is more uniform around the aluminum powder than the ball mill under 75 r/min, the ball milling speed is preferably 50 r/min. As the content of aluminum powder increases, the distribution of alumina in aluminum powder is large and uniform, and there is a small amount of pinning. It provides a package-like composite for the preparation of cermet with a wrapped structure and the thermal conduction mechanism of the controlled cermet.
Mn3O4 Nanosheets Decorated on Graphene Modified Carbon Cloth with Improved Pseudocapacitive Performance
Authors: Dou Zhen Jun , Qin Zong Yi
Published: September 2020

Mn3O4 nanosheets were deposited electrochemically on graphene modified carbon cloth (G–CC). The graphene layer improved significantly the hydrophilic property of carbon cloth and its compatibility with active materials, as a result, lower resistance and better structural stability were obtained for Mn3O4/G–CC compared with those for the electrode based on neat carbon cloth. Furthermore, the Mn3O4/G–CC possessed a capacitance of 1335 mF cm–2 at a current density of 2 mA cm−2, and a capacitance retention of up to 88 % after 2000 cycles at 10 mA cm–2. It is believed that manganese oxide was anchored strongly on graphene layer through C–O–metal bonds, and the graphene layer on the surface of the CC could serve as elastic buffering layers to release the strain within manganese oxide, resulting the remarkable improvements in electrochemical performance. These excellent characteristics make this kind of the composites promising candidates as high performance electrodes for supercapacitor.
Enhance Cellulose Film Production from Oil Palm Trunk under NaOH/Urea Solution at Low Temperature
Authors: Phruksaphithak Nantharat , Goomuang Nophadon , Jaema Nattawut
Published: September 2020

The effect of cellulose from oil palm trunk (OPT) concentrations (1, 3, 5, and 7 wt %), which were treated various times with urea mixed in NaOH aqueous solution on fabricating cellulose film, were studied. The results showed cellulose from OPT film was successfully prepared through cellulose was dissolved in 7wt% NaOH/12wt% urea aqueous solution at 4°C. The function group was evaluated by FTIR, whereas the physical properties were observed by a camera. The photographs of cellulose film concluded that 5wt% cellulose from OPT had a smoother surface than other ratios. The FTIR result showed that the vibration peak confirmed that cellulose from OPT successfully produced cellulose film. The mechanical properties result showed that urea mixed into cellulose/NaOH suspension after 24 hr presented better mechanical properties than urea mixed immediately. This research provided a friendly environmental system for the preparation of the packaging films.
Study on Open-Graded Cold Mend Material’s Road Performance of Porous Asphalt Pavement
Authors: Chen Geng Tian , Xie Jian Guang , Wang Zhao Xin , Zhang Bing Yang
Published: September 2020

Porous asphalt pavement is widely used in domestic engineering, whose repair technology is still a problem in engineering application. Rut specimens for porous asphalt pavement are made, so the actual repairing condition of porous asphalt pavement can be simulated after slotting and repairing by open-graded cold mend material. In addition, the repair efficiency of open-graded cold mend material was verified. The results of the pullout test show that when the spraying dosage is 0.75L/m2, the bond behavior of bonding oil is best excellent. The Accelerated Loading Facility (ALF) indicated that the cold mend material has favorable abrasion resistance properties, and the abrasion resistance is less effected by the spraying dosage of bonding oil. Meanwhile, it’s reveled that the permeability coefficient of rut specimen repaired by cold mend material decreases with the increase of spraying dosage of bonding oil in the permeability test, and too much bonding oil will seriously affect the rut specimen’s original permeability.
Research on Early Warning System for Plastic Shrinkage Cracking of Cement Mortar Based on Constitutive Equations
Authors: Ma Yi Ping , Fu Jie , Zhang Han , Ma Zheng Hang , Yu Shao Tong , You Lu , Zhang Le , Li Guo You , Wang Qiong Qiong , Yang Xiao Jie
Published: September 2020

Aiming at the plastic shrinkage cracking of cement mortar, the constitutive equations of it in laboratory were established by testing plastic tensile strength, plastic capillary shrinkage stress and water loss evaporation rate of mortar under different composition parameters, environmental parameters, initial structural parameters and constraints condition parameters. And the early warning system of it was explored. The results showed that the seven-element constitutive equation of plain mortar and the nine-element constitutive equation of mortar with polyvinyl alcohol (PVA) fiber can effectively predict the plastic shrinkage cracking state of mortar outdoors. An early warning system for it was initially established.
Ertical Butt Welding Technology of Q355g Small Diameter Pipe TIG
Authors: Wang Zhi Ling
Published: September 2020

In this paper, according to the requirements of welder's technical qualification specification, combined with the practice training topic of TIG vertical butt welding, we have repeatedly trained the operation process of TIG vertical butt welding of q355g steel pipe with specification of Φ 60 х 5,And we adopt the following process measures in the welding process: before welding, we make V-shaped tooling by combining with the workpiece ; when welding, we choose reasonable process parameters; at the same time, we pay more attention to the welding operation skills of backing and cover layer. Therefore, we have achieved satisfactory weld quality, and the relevant experience has been popularized in the teaching process of the school to obtain good evaluation.
X-Ray Diffraction Analysis of YSAG:Yb Ceramic Powders with Different Stoichiometry
Authors: Nikova Marina S. , Vakalov Dmitry S. , Tarala Vitaly A. , Chikulina Irina S. , Malyavin Fedor F. , Ambarcumov Mikhail G.
Published: September 2020

Synthesis of YSAG:Yb ceramic powders with different stoichiometry by chemical precipitation method was carried out. It has been established that scandium can replace both dodecahedral and octahedral positions of garnet. It is shown that scandium is embedded in those positions that become available to it when the YAG:Yb composition deviates from stoichiometric. Thus, scandium can compensate for the lack of one of the components of the oxide composition Y2O3, Yb2O3, and Al2O3 during the formation of the garnet phase.
The Research for Approaches to Increase Power of the Compact THz Emitters Based on Low-Temperature Gallium Arsenide Heterostructures
Authors: Nomoev Sergey , Vasilevskii Ivan , Vinichenko Alexander
Published: September 2020

The design and technological conditions for the manufacture of photoconductive antennas based on low-temperature gallium arsenide (LT-GaAs) have been developed. The optimized photoconductive THz antenna is made based on LT-GaAs with the flag geometry of the contacts and with the interdigitated structure including metal closing through the dielectric of each second period. LT-GaAs samples were obtained by molecular beam epitaxy at temperatures of 210 °C, 230 °C, 240 °C on GaAs substrates (100). Dark and photocurrent were measured depending on the bias voltage of the LT-GaAs heterostructure at the EP6 probe station. Full wave finite element method solver has been used to investigate the proposed plasmon PCA electrical and optical behavior by combining the Maxwell's wave equation with the drift-diffusion/Poisson equations.
XRD Quantitative Analysis of Cathode Deposition Formed by DC Arc-Discharge in Water
Authors: Bayanjargal Erdene , Vanchinkhuu Jigmeddorj , Erdenebat Tserenjav , Otgonbaatar Myagmar
Published: September 2020

In this study, we aimed to estimate the weight fraction of crystalline phases in a cathode deposition formed by DC arc-discharge between graphite electrodes in water via the XRD method and CARBON XS program based on Shi model, which takes into account disorder and stacking faults in a graphite structure. The structural computation of graphitic carbon materials for comparison was done by using CARBON XS according to Shi model. From the study, we observed that the total weight fraction of 2H hexagonal and 3R rhombohedral ordered structures of graphitic carbon decreases from 77.69% to 48.98%, whereas the weight fraction of random shift and stacking faults increases from 22.31% to 51.02% as compared to these parameters belonging to pure graphite structure during the arc-discharge process.
Study of Structural and Magnetic Properties of Spinel Zn Doped Cobalt Ferrites
Authors: Feng B. Chun , Tegus Ojiyed , Ochirkhyag T. , Odkhuu Dorj , Tsogbadrakh Namsrai , Sangaa Deleg , Davaasambuu Jav
Published: September 2020

Herein, the spinel Co1-xZnxFe2O4 (x = 0.0, 0.2, 0.4 and 0.6) powder samples have been prepared by the solid-state reaction method. We have carried out the measurements of crystal structure, element analysis, material characterization, magnetic property and Curie temperature using the X-ray diffraction (XRD), Energy-dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS) and vibrating sample magnetometer, and the first-principles calculations within the framework of the density functional theory (DFT). The EDS measurement indicates that the Co1-xZnxFe2O4 powder samples have been successfully synthesized and exhibited the cubic spinel structures. Both the lattice constant and crystallite size increase with the Zn concentration due to the larger ionic radius of Zn2+ ion than the Co2+ ion. The concentration ratio of the Co2+ and Co3+ ions can be predicted by the distribution of cations between the A and B sites by the XPS measurement. For the magnetic properties, the residual magnetization, coercivity and Curie temperature decrease monotonically as the Zn concentration increases, while the saturation magnetization initially increases and then decreases at the room temperature. For the Co0.8Zn0.2Fe2O4 sample, the magnetic saturation reaches the maximum value of 62.98 Am2kg-1, due to a large amount of the Co3+ ions. The adequate replacement of Zn ion for the Co site can improve the magnetic properties of spinel Co1-xZnxFe2O4 powders, and effectively regulates the Curie temperature.
A New Synthesis Method for Lithium Tantalate Charge Doped with Rare-Earth Elements
Authors: Masloboeva Sofia M. , Palatnikov Mikhail N. , Arutyunyan Larisa G.
Published: September 2020

A method was developed for synthesis of a single phase lithium tantalate charge doped by rare earth elements (TR) from highly pure solutions containing tantalum. The method is based on obtaining and thermal treatment of citrate precursor containing Li, Ta and TR. Charge samples were obtained due to suggested technological scheme; the dopant had given concentration and was chemically uniformly distributed. The charge can be applied both in single crystal growing technology and at obtaining of functional ceramics based on LiTaO3:TR.
Study on Modified High Voltage (5V) Spinel Lithium Manganate Used for Energy Storage Lithium Titanate Batteries
Authors: Wu Dan , Li Wei , Tegus Ojiyed , Bater Si Qin
Published: September 2020

Solid electrolyte Li1.4Al0.4Ti1.6 (PO4)3 was used to coat high voltage (5V) spinel lithium manganate. The modified high voltage spinel lithium manganate was used as positive electrode and the lithium titanate as negative electrode. A type of 10Ah energy storage battery was assembled. Charge-discharge and cycle life tests of these batteries were carried out at different temperatures and rates. The results show that coating high voltage spinel lithium manganate improves the high temperature cycle performance of the lithium titanate batteries. The capacity retention ratio of the lithium titanate batteries with the coated high voltage lithium manganate as cathode material increases from 74.8% to 86.5% at 60°Cafter 2000 cycles compared to the lithium titanate batteries with the uncoated high voltage lithium manganite as cathode material. However, the cycle performance is not affected at-30 °C. The low temperature rate performance of lithium titanate batteries is improved by coating high voltage lithium manganate. When the discharge rate is 20 C at-30°C, 90.6% of the 1 C charge capacity at room temperature of the lithium titanate battery with the coated high voltage lithium manganate as cathode materialcan be delivered, while the lithium titanate battery with the un-coated high voltage lithium manganate as cathode material can only deliver 80.2% of the 1 C charge capacity at room temperature.
Higher Frequency and Increased Expression of Molecules Associated with Suppression on T Regulatory Cells from Newborn Compared with Adult Nonhuman Primates
Authors: Holbrook Beth C. , Alexander-Miller Martha A.
Published: September 2020

T regulatory cells (Tregs) play a critical role in controlling the immune response, often limiting pathogen-specific cells to curb immune-mediated damage. Studies in human infants have reported an increased representation of Tregs in these individuals. However, how these cells differ from those in adults at various sites and how they respond to activation signals is relatively unknown. In this study, we used a newborn nonhuman primate model to assess Treg populations present at multiple sites with regard to frequency and phenotype in comparison with those present in adult animals. We found that Foxp3+ cells were more highly represented in the T cell compartment of newborn nonhuman primates for all sites examined (i.e., the spleen, lung, and circulation). In the spleen and circulation, newborn-derived Tregs expressed significantly higher levels of Foxp3 and CD25 compared with adults, consistent with an effector phenotype. Strikingly, the phenotype of Tregs in the lungs of adult and infant animals was relatively similar, with both adult and newborn Tregs exhibiting a more uniform PD-1+CD39+ phenotype. Finally, in vitro, newborn Tregs exhibited an increased requirement for TCR engagement for survival. Further, these cells upregulated CD39 more robustly than their adult counterpart. Together, these data provide new insights into the quantity of Tregs in newborns, their activation state, and their potential to respond to activation signals.
SCCmec typing and Panton-valentine leukocidin occurrence in methicillin resistant Staphylococcus aureus (MRSA) isolates from clinical samples of Ahvaz,southwest of Iran
Authors: Bahrami Nikou , Motamedi Hossein , Reza Tofighi Seyyedeh Elham , Akhoond Mohammad Reza
Published: September 2020

Resistance to methicillin in methicillin resistant Staphylococcus aureus (MRSA) is dependent on mecA gene located on staphylococcal cassette chromosome (SCC). Both SCCmec type and Panton-Valentine leukocidin (PVL) affect S. aureus pathogenicity. Aim of this study was to investigate the prevalence of SCCmecA types and pvl genes among MRSA isolates from inpatients. During this cross-sectional study on 100 clinical isolates, following antibiotic susceptibility test, screening of mecA and pvl genes, as well as SCCmec typing, was done in a multiplex PCR technique. From the studied samples, 58 isolates were recognized as MRSA. The frequency of mecA and pvl was 58% and 4%, respectively. All of the MRSA were resistant to cefoxitin and had the highest sensitivity to chloramphenicol. The majority (77.5%) of MRSA was originated from wound samples. The SCCmec III was the most frequent type (22.4%) in these samples. The pvl positive isolates were from SCCmec IVb and V, thus meaning they are from CA-MRSA. These results show a high prevalence of MRSA in the studied region and a widespread prevalence of SCCmec I-V types. Furthermore, high prevalence of SCCmec III indicates the prevalence of multidrug resistant MRSA. This finding is a serious alarm for medical health care practitioners for the correct use of antibiotics in order to limit the spread of multidrug resistant strains. In addition, with regard to life threatening infections caused by pvl harbouring strains, early diagnosis and treatment of infections caused by these isolates should be mandatory.
First case of fungal rhinosinusitis due to Aspergillus nomius in a child with aplastic anaemia
Authors: Oz Yasemin , Aslan Muge , Gundogdu Nuray , Bor Ozcan
Published: September 2020

Recently, infections caused by Aspergillus species have increased dramatically. Invasive aspergillosis (IA) is one of the most important causes of morbidity and mortality in immunocompromised patients, such as those with haematological malignancies who undergo chemotherapy, bone marrow and solid organ transplant recipients, and patients with other immunodeficiency. The most common species causing invasive infections include Aspergillus fumigatus, followed by Aspergillus flavus. Aspergillus nomius is an anamorphic species belonging to Aspergillus section Flavi, which currently include 22 species that can be grouped into seven clades (Aspergillus flavus, Aspergillus tamarii, Aspergillus nomius, Petromyces alliaceus, Aspergillus togoensis, Aspergillus leporis and Aspergillus avenaceus) based on morphological characters, sequence data, and extrolite profiles. These species may also produce toxic and carcinogenic aflatoxins. However, Aspergillus nomius is an emerging pathogen as a cause of IA; we found only two reported cases of invasive infection caused by this fungus in literature up till now. We reported a case of fungal rhinosinusitis caused by Aspergillus nomius in a child with aplastic anaemia and to our knowledge, it is the first case as an agent of rhinosinusitis. The isolate was identified by sequencing based methods.
The clinical relevance of pathogen Aerococcus urinae identification by MALDI-TOF mass spectrometry: a case of sepsis in 86-year-old Caucasian male
Authors: Intra Jari , Sarto Cecilia , Serra Giuseppe , Brambilla Paolo
Published: September 2020

The infrequency of urinary tract and blood stream infections caused by Aerococcus urinae is most probably due to the difficulties in the identification of this bacterium using standard microbiological methods. With the introduction of more sensitive and accurate techniques in clinical microbiology, such as genetic approaches and Matrix-Assisted Laser Desorption/Ionization-Time Of Flight (MALDI-TOF) mass spectrometry (MS), the incidence of infections due to A. urinae increased. Herein, we described a case of urinary tract and bloodstream infection caused by A. urinae, which occurred in an 86-year-old Caucasian man with a previous history of prostate cancer. The identification of A. urinae was performed by MALDI-TOF MS, since this microorganism cannot be identified by biochemical reactions. In this report, we highlight the need to consider MALDI-TOF MS as technique of choice for A. urinae identification in the presence of subjects with predisposing factors, such as old age, male gender, and genitourinary tract pathologies.
Largest intracranial calcified hydatid cyst: A case report with review of literature
Authors: Agrawal Vivek , Giri Pramod
Published: September 2020

Cerebral hydatid disease is a peculiar manifestation of echinococcosis, an infection acquired from Echinococcus tapeworm, in its larval stage. It symbolizes only 2% of all the cerebral space occupying lesions. It is frequently observed in children and young adults. In this paper, we report an exceptional case of intracranial solitary calcified hydatid cyst in a 25 year old male, shepherd by occupation, presenting with history of difficulty in walking and convulsions for the last 20 years. Craniotomy was carried out and an intact calcified mass weighing around 300 grams was excised. It is the largest intracranial calcified hydatid cyst excised till date and is first of its kind.
Supratentorial embryonal tumor in adult patient: Case report and literature review
Authors: Munoz Montoya Juan , Santamaria Rodríguez Paula , Duarte Mora Diana , Benavidez Rojas Mónica , Cortes Jaramillo Elsa , Chacón Zambrano Leonardo
Published: September 2020

Embryonal tumors are the new nomenclature of the primitive neuroectodermal tumors or PNET. Their supratentorial location and their manifestation in adult population are not very frequent. Embryonal tumors are conformed from undifferentiated neuroepithelial cells that have the ability to show differentiation to several cell lines. Next is presented a case from an adult male patient with a clinical headache pictures and convulsions. With imaging study that shows a meningeal enhancement with frontal lobe infiltration with histopathological study of embryonic tumor with areas of glial differentiation.
Patterns of neurosurgical conditions at a major government hospital in Cambodia
Authors: Kim Miri , Yoo Chung , Lee-Park Owen , Nang Sam , Vuthy Din , Park Kee , Vycheth Iv
Published: September 2020

Background: Low- and middle-income countries (LMICs) have a growing and largely unaddressed neurosurgical burden. Cambodia has been an understudied country regarding the neurosurgical pathologies and case volume. Rapid infrastructure development with noncompliance of safety regulations has led to increased numbers of traumatic injuries. This study examines the neurosurgical caseload and pathologies of a single government institution implementing the first residency program in an effort to understand the neurosurgical needs of this population. Methods: This is a longitudinal descriptive study of all neurosurgical admissions at the Department of Neurosurgery at Preah Kossamak Hospital (PKH), a major government hospital, in Phnom Penh, Cambodia, between September 2013 and June 2018. Results: 5490 patients were admitted to PKH requiring neurosurgical evaluation and care. Most of these admissions were cranial injuries related to road traffic accidents primarily involving young men compared to women by approximately 4:1 ratio. Spinal pathologies were more evenly distributed in age and gender, with younger demographics more commonly presenting with traumatic injuries, while the older with degenerative conditions. Conclusions: Despite increased attention and efforts over the past decade, Cambodia's neurosurgical burden mirrors that of other LMICs, with trauma affecting most patients either on the road or at the workplace. Currently, Cambodia has 34 neurosurgeons to address the growing burden of a country of 15 million with an increasing life expectancy of 69 years of age, stressing the importance of better public health policies and urgency for building capacity for safe and affordable neurosurgical care.
Trigeminal neuralgia secondary to cerebellar arteriovenous malformation: A report of two cases
Authors: Tjahjadi Mardjono , Wijaya Vincent , Serrone Joseph , Caropeboka Muhammad
Published: September 2020

Trigeminal neuralgia (TN) secondary to cerebellar arteriovenous malformation (cAVM) is a rare condition with only few reports existing in the literatures. Given to its rarity, the treatment armamentarium is still controversial. We reported our experiences treated two cases of TN secondary to cAVM using different strategies. The first case was successfully treated by a combination of gamma knife radiosurgery and microvascular decompression (MVD) of the trigeminal nerve. The second case was successfully treated by one-step microsurgical AVM resection and MVD of the trigeminal nerve. Postoperative immediate pain relief was achieved in both patients. Microsurgical procedure is still playing an important role in treating TN secondary to cAVM.
”White cord syndrome” of acute tetraplegia after posterior cervical decompression and resulting hypoxic brain injury
Authors: Kalidindi Kalyan , Sath Sulaiman
Published: September 2020

White cord syndrome (WCS) is a rare case of severe neurological deterioration after surgical decompression for cervical myelopathy. It was proposed to be secondary to an ischemia/reperfusion injury. An association of WCS with a hypoxic brain injury (HBI) has not been documented. A 63-year-old man presented to us with progressive symptoms of cervical myelopathy. Computed tomography scan and magnetic resonance imaging (MRI) scan findings were suggestive of an ossified posterior longitudinal ligament with cord atrophy and myelomalacia changes. He was managed surgically by decompression and fusion through a posterior approach. During the surgery, there was a sudden loss of neuromonitoring signals after laminectomy, and wake-up assessment revealed neurological deterioration. Immediate postoperative imaging revealed adequately placed screws and adequate cord decompression. A high dose of intravenous steroids was given. Repeat MRI scan on the 3rd postoperative day suggested cord edema over a large area on T2-weighted images. He was diagnosed as WCS and managed conservatively. He had persistent abdominal distension postoperatively, and a diagnostic endoscopy was advised. At the start of the procedure, the patient had a sudden-onset loss of consciousness. Electrocardiogram suggested bradyarrhythmias with hypotension. The patient was resuscitated, intubated, and shifted to intensive care unit. He was diagnosed to have a HBI. He was managed with multidisciplinary rehabilitation and discharged at 4 months' postoperatively with stable vitals. There was no improvement in the neurology or his consciousness. Spine surgeons have to be aware of this potentially disastrous complication of WCS. One should take adequate postoperative care to avoid preventable complications like HBI associated with it.
Neglected bilateral facet dislocation of the cervical spine with intact neurology: Reduction technique
Authors: Jain Mantu , Khuntia Susanta , Rao Bhaskar
Published: September 2020

Bilateral cervical facet dislocation is a serious injury that in majority cause neurologic deficit requiring prompt medical attention. Rarely, they retain normal neurology due to spontaneous decompression even though patients can have objective myelopathic or root compression signs. Neglected cases with normal neurology are uncommon with only few of them reported in the literature but their management is still a matter of debate. Here, we report a case of a 26-year-old female who had neglected bilateral facet dislocation with neck stiffness that was operated with posteroanterior approach with near-complete reduction and intact neurology. We describe the technique employed and discuss the literature.
A review of common endoscopic intracranial approaches
Authors: Darbar Aneela , Mustansir Fatima , Hani Ummey , Sajid Mir
Published: September 2020

With the evolution of surgical techniques, endoscopy has emerged as a suitable alternative to many instances of more invasive methods. In this review article, we aim to discuss the endoscopic advancements, procedural details, indications, and outcomes of the most commonly practiced neuroendoscopic procedures. We have also summarized the uses, techniques, and challenges of neuroendoscopy in select neurosurgical pathologies.
Analysis of the surgical outcome of unruptured intracranial saccular aneurysms in octogenarians (80–89 Years)
Authors: Thavara Binoy , Yamada Yasuhiro , Joshi Girish , Tanaka Riki , Miyatani Kyosuke , Devareddy Gowtham , Nakao Kazutaka , Kawase Tsukasa , Kato Yoko
Published: September 2020

Background: The prevalence of unruptured intracranial aneurysms is increasing in elderly population in Japan. Octogenarians (80–89 years) are more prone to complications due to increased age, comorbidities, increased risk of vasospasm, and treatment risks. Aim: The aim is to study the surgical outcome of unruptured intracranial saccular aneurysms in elderly patients aged between 80 and 89 years. Patients and Methods: A retrospective study was conducted involving all the cases of unruptured intracranial saccular aneurysms operated surgically in elderly patients aged between 80 and 89 years. All the cases operated between January 2017 and October 2019 were included in the study. The preoperative neurological status was assessed using the Glasgow Coma Scale (GCS). The comorbidities and risk factors involved were assessed. Postoperative neurological status was assessed by (1) postoperative GCS score and by the (2) presence or absence of the motor weakness of limbs. Results: Thirty-three aneurysms were operated in 27 patients. Two patients were operated two times at separate occasions for different aneurysms during the study period and hence making a total of 29 surgeries. The age range was 80–88 years, with a mean of 82.4 years ± 2.64 standard deviation (SD). There were 7 (24.1%) males and 22 (75.86%) females. All the patients had a preoperative GCS score of 15/15 without focal neurological deficit. The mean size (mm) of the aneurysms was 6.57 ± 4.04 SD. There were 31 (93.94%) aneurysms in the anterior circulation and 2 (6.06%) aneurysms in the posterior circulation. The comorbidities and risk factors were analyzed and found to be not influencing the outcome of the patients. Clipping was done in 32 aneurysms. One case of posterior inferior cerebellar artery (PICA) aneurysm underwent occipital artery to PICA bypass surgery. The postoperative complications include chronic subdural hematoma (CSDH) in 7 (24.13%) patients, extradural hematoma in 1 (3.4%), meningitis in 1 (3.4%), and lower cranial nerve palsy in 1 (3.4%) patient. All the patients were discharged with GCS score 15/15 without motor weakness of the limbs. The mean duration of stay was 16.62 days ± 9.98 SD. Conclusion: Surgery for unruptured saccular aneurysms in octogenarians has got a good result in the tertiary care facility. Advanced age alone should not be considered for preferring coiling over clipping. Octogenarians are more prone to developing postoperative CSDH.
Closure of skull base defects after endonasal endoscopic resection of planum sphenoidale and tuberculum sellae meningiomas
Authors: Dolci Ricardo , Encinas Williams , Monteiro Amanda , Kozechen Rickli Jeniffer , de Souza Jamile , Todeschini Alexandre , Padilha Igor , Zuppani Henrique , Leite dos Santos Américo , Lazarini Paulo
Published: September 2020

Background: The expanded endoscopic endonasal transplanum transtuberculum approach allows tumor removal by minimally invasive procedures. A large dural and bone defect is created during the surgical procedure, increasing the risk of postoperative cerebrospinal fluid (CSF) leakage. Objective: The aim of this study is to describe a surgical technique and complications observed in patients undergoing endonasal resection of planum sphenoidale and/or tuberculum sellae meningiomas. Methods: A retrospective analysis was performed of patients with planum sphenoidale and/or tuberculum sellae meningiomas after expanded endoscopic endonasal resection between June 2013 and August 2018, in which autologous grafts, fascia lata inlay, and nasoseptal flap onlay were used for closure of skull base defects. Results: Ten patients were included in the analysis. No cases of postoperative CSF leakages or meningitis were reported, whereas two patients evolved with postoperative infectious complications (fungal ball in right frontal sinus and brain abscess). The skull base defect created for resection measured, on average, 3.58 cm2. Conclusion: Our experience suggests that closure of skull base defects using combined fascia lata inlay and nasoseptal flap onlay is effective for preventing postoperative CSF leakage in resection of planum sphenoidale and/or tuberculum sellae meningiomas, and offers high reproducibility due to its low cost.
Missing disc fragment: A rare surgical experience
Authors: Mallepally Abhinandan , Gantaguru Amrit , Marathe Nandan , Meena Sanjay , Tandon Vikas
Published: September 2020

About 35%–72% of lumbar disc herniations are associated with fragment migration. However, the posterior epidural migration is rare. We present a strange situation encountered during surgical decompression of the posterior migrated fragment. A 72-year-old male presented with a history of pain radiating to the left lower limb and Grade 3 power of the extensor hallucis longus. Magnetic resonance imaging revealed a prolapsed intervertebral disc and a possible posterior epidural migration of disc fragment. Routine surgical steps for microdiscectomy were followed after confirmation of level using fluoroscopy. However, the extruded disc fragment was not seen, and both exiting and traversing roots were free with adequate mobility. After extensively searching for a disc in the spinal canal, suction fluid was filtered through a surgical mop used as a sieve. Material collected was sent for histopathological study. Biopsy report confirmed material filtered was indeed the intervertebral disc. Thus, accidental suction of disc material in case of the posterior epidural migrated disc is a possibility, and we should be vigilant about this scenario to avoid disaster.
High-flow bypass with radial artery graft for cavernous carotid aneurysm
Authors: Kumar Ambuj , Sharma Raghavendra , Tanaka Riki , Yamada Yashuhiro , Takizawa Katsumi , Kato Yoko
Published: September 2020

Cavernous carotid aneurysms can be managed by different surgical as well as endovascular methods. The aim of treatment is to exclude the aneurysm from circulation and maintain normal cerebral blood flow. We are reporting a case of incidentally detected CCA managed by high flow bypass with radial artery graft. We discuss the surgical technique and nuances of high flow bypass surgery.
Nerve to the zygomaticus major muscle for facial reanimation surgery: A cadaveric study for branching patterns and axonal count
Authors: Jirawatnotai Supasid , Kaewpichai Kitipong , Tirakotai Wuttipong , Mothong Wilaiwan , Kaewsema Atitaya , Sriswadpong Papat
Published: September 2020

Background: In facial reanimation surgery, higher donor facial nerve axonal load yields a superior outcome. Nerves supplying the zygomaticus major muscle are primary donors for the grafting procedure; however, their topography has not been studied in detail. This study identified potential donor nerves by quantifying axon loads of the zygomaticus major muscle through histological analysis of cadaveric specimens. Materials and Methods: Forty-three hemifaces from 26 fresh human cadavers were studied. Branching patterns of nerves were classified according to their shapes. All branches of interest were sectioned and stained for an axon count. The potential donors were mapped into each tributary of nerves supplying the zygomaticus major. Results: Branching patterns were categorized into five types: Y-type (28%), X-type (28%), H-type (19%), E-type (14%), and F-type (11%). The mean number of axons in the most superiorly and proximally located main branches was 1387.33 ± 406.59 in Y-type, 1021.42 ± 187.79 in X-type, 1222.75 ± 193.82 in H-type, 1496.17 ± 364.567 in E-type, and 1353.40 ± 256.07 in F-type (P > 0.05). A topographic relation between facial nerves supplying the zygomaticus major muscle and their mean axonal load was illustrated. The zygomatic/buccal branches were found within 5 mm from Zuker's point in 100% of X-, Y-, H-, and E-type and 75% of F-type specimens. Conclusions: Most proximal facial nerve branches supplying the zygomaticus major, arising at the anterior border of a parotid gland, contained over 900 axons in all five branching types. The primary subbranches may be used in selected cases if donor weakness is a concern. Further, our study provides evidence that demonstrates the precision of Zuker's point.
On a family of torsional creep problems in Finsler metrics
Authors: Fărcăşeanu Maria , Mihăilescu Mihai , Stancu-Dumitru Denisa
Published: September 2020

The asymptotic behavior of solutions to a family of Dirichlet boundary value problems, involving differential operators in divergence form, on a domain equipped with a Finsler metric is investigated. Solutions are shown to converge uniformly to the distance function to the boundary of the domain, which takes into account the Finsler norm involved in the equation. This implies that a well-known result in the analysis of problems modeling torsional creep continues to hold in this more general setting.
The Clifford-cyclotomic group and Euler–Poincaré characteristics
Authors: Ingalls Colin , Jordan Bruce W. , Keeton Allan , Logan Adam , Zaytman Yevgeny
Published: September 2020

For an integer

$n\geq 8$
divisible by

$4$
, let

$R_n={\mathbb Z}[\zeta _n,1/2]$
and let

$\operatorname {\mathrm {U_{2}}}(R_n)$
be the group of

$2\times 2$
unitary matrices with entries in

$R_n$
. Set

$\operatorname {\mathrm {U_2^\zeta }}(R_n)=\{\gamma \in \operatorname {\mathrm {U_{2}}}(R_n)\mid \det \gamma \in \langle \zeta _n\rangle \}$
. Let

$\mathcal {G}_n\subseteq \operatorname {\mathrm {U_2^\zeta }}(R_n)$
be the Clifford-cyclotomic group generated by a Hadamard matrix

$H=\frac {1}{2}[\begin {smallmatrix} 1+i & 1+i\\1+i &-1-i\end {smallmatrix}]$
and the gate

$T_n=[\begin {smallmatrix}1 & 0\\0 & \zeta _n\end {smallmatrix}]$
. We prove that

$\mathcal {G}_n=\operatorname {\mathrm {U_2^\zeta }}(R_n)$
if and only if

$n=8, 12, 16, 24$
and that

$[\operatorname {\mathrm {U_2^\zeta }}(R_n):\mathcal {G}_n]=\infty $
if

$\operatorname {\mathrm {U_2^\zeta }}(R_n)\neq \mathcal {G}_n$
. We compute the Euler–Poincaré characteristic of the groups

$\operatorname {\mathrm {SU_{2}}}(R_n)$
,

$\operatorname {\mathrm {PSU_{2}}}(R_n)$
,

$\operatorname {\mathrm {PU_{2}}}(R_n)$
,

$\operatorname {\mathrm {PU_2^\zeta }}(R_n)$
, and

$\operatorname {\mathrm {SO_{3}}}(R_n^+)$
.