bluuebunny/crossref_metadata_2025 huggingface dataset:
INFLUENCE OF DEFUNCTIONING COLOSTOMY AFTER LOW ANTERIOR RESECTION FOR RECTAL CANCER ON EARLY POSTOPERATIVE PERIOD
Authors: Zitta D. V. , Subbotin V. M.
Published: June 2019

The AIM of this study was to evaluate the influence of defunctioning colostomy after low anterior resection for cancer on early postoperative period and effectiveness of Fast Track protocol. MATERIALS. Retrospective analysis of medical records of 186 patients with rectal cancer who underwent anterior resection of the rectum in our department was done. All patients were allocated into 2 groups - conventional (had conventional perioperative care) and optimized (perioperative treatment according to Fast Track protocol). Both groups were subdivided into 3 subgroups (unprotected anastomosis, defunctioning colostomy and Hartmann procedure). The following data were analysed: average time of operation, operative bloodloss, volume of infusion and urination, time of mobilization removement of dranages and catheters, postoperative complications. RESULTS. Age, sex, comorbidities had no effect on decision about a preventive colostomy. The main reason for preventive colostomy was a middle-rectum location of a tumor. Preventive colostomy didn’t affect the course of early postoperative period in groups. Defunctioning colostomy effectively prevent catastrophic consequences of anastomotic leakage and didn’t compromise Fast Track protocol. CONCLUSION. Defunctioning colostomy did not reduce postoperative anastomotic leak rate, but mitigate consequences of an anastomotic leakage. Defunctioning colostomy did not affect the course of early postoperative period and Fast Track protocol.
SIMULTANEOUS AND STAGED RESECTIONS FOR SYNCHRONOUS COLORECTAL LIVER METASTASES: META-ANALYSIS
Authors: Ponomarenko A. A. , Shelygin Yu. A. , Rybakov E. G. , Achkasov S. I.
Published: June 2019

AIM. To analyze the short-term and long-term outcomes two alternative surgical strategies: 1) simultaneous resections for colorectal cancer and synchronous colorectal liver metastases;2) conventional surgery for the primary tumor during the initial operation. After time, the liver resection is performed at a second operation METHODS. Meta-analysis was performed to compare outcomes simultaneous resections for colorectal cancer and synchronous colorectal liver metastases and staged surgery. Tumor localization, spread and number of metastasis, extent of operation, blood loss, length of hospital stay, postop mortality, complication rates, overall survival rates were analyzed. RESULTS. Twenty-nine studies with 5518 patients were included in meta-analysis. Multiple (р=0,007) and bilobed (р=0,0004) metastasis were more often in patients in group ofstaged resections. Major hepatectomy was also performed more often in group of staged resections. There were no significant differences in blood loss and postopirative mortality rates (p>0,05). Complication rate in group of simultaneous resections was lower than in group of staged resections (0R=0,8, 95 %CI: 0,7-1.0, p=0,048). 3- and 5-year overall survival rates were similar in both groups: 54% vs 55 %, and 37% vs 38%, respectively (р=0,007). CONCLUSION. Simultaneous resection of the primary tumor and the minor liver resection or extended hepatectomy in selected patients didn’t adversely affect on complications and mortality rates in equivalent long-term survival compared to staged liver resection. An important limitation of the present study is the bias and heterogeneity in compared groups due to retrospective data over the 20-year period.
INCIDENCE OF TOXIN - PRODUCING STRAINS OF CLOSTRIDIUM SPP. AMONG MEDICAL STAFF IN COLOPROCTOLOGY DEPARTMENT
Authors: Achkasov S. I. , Sukhina M. A. , Sushkov O. I. , Safin A. L. , Frolov S. A.
Published: June 2019

INTRODUCTION. The spread of microorganisms of the genus Clostridium in the population is 15 %. This phenomenon has not been studied in coloproctology department in Russia. AIM. To estimate the spread of toxin - producing strains of Clostridium spp. among the medical staff in coloproctology department. MATERIALS AND METHODS. There were analysed 39 of intraluminal faeces. The material was examined for the presence of glutamate dehydrogenase, toxins A and B of C.difficile using the immunochromatographic method. To detect microorganisms a matrix-activated laser desorption ionization time-of-flight mass spectrometry technique was used. RESULTS. Positive tests for toxins A and B of C.difficile were in 28 (71,8 %) of 39 samples. We have identified the culture of the genus Clostridium in 24 (61,5 %) of the 39 samples of intraluminal faeces. 17 (70,8 %) of these samples had positive tests for C.difficile toxins and 7 (29,2 %) was negative. In addition to C. difficile (3) others Clostridium were identified: C.perfringens (17), C.bifermentas (4), C.tertium (3), C.disporicum (2), C.sordellii (2). CONCLUSION. C.difficile was identified in 3 (7,7 %) cases. The spread of Clostridium microorganisms in medical stuff is almost 5 times higher than the average in the population. Professional activity is a risk factor for the spread of toxic strains of the genus Clostridium.
SHORT-TERM RESULTS OF SURGICAL TREATMENT FOR SYNCHRONOUS LIVER METASTASES OF RECTAL CANCER
Authors: Ponomarenko A. A. , Shelygin Yu. A. , Rybakov E. G. , Achkasov S. I.
Published: June 2019

BACKGROUND. Staged surgery in cases of rectal cancer liver metastases is preferred method in routine clinical practice. Another choice is simultaneous operations. Our prospecpective study compares short-term outcomes of patients with synchronous rectal liver metastases treated by simultaneous or staged surgery. METHODS. 108 suitable patients were treated in State Scientific Centre of coloproctology named after A.N.Ryzhih, Moscow, Russia between January 2013 and February 2017. Simultaneous rectal and hepatic resections were performed in 78 patients; 30 patients underwent delayed hepatectomy. Short-term outcomes were analyzed. RESULTS. Major liver resections were rarely performed in group of simultaneous operations: 22 % vs 56% (р=0,0001). Anterior resection performed more often in simultaneous group 48/78 (62%) vs 12 (40%) (р=0,053), respectively. There was no difference in mortality and complications rates between major liver resections in both groups: 0 vs 3 % and 57% vs 28%, respectively. Age ≤61 y.o. (OR=13; 95 % CI=1,3-120), size of the largest metastasis in the liver >2.1 cm (OR=6,6; 95 % CI=1,8-23), staged surgery (OR=6,9; 95 % CI=1,5-31) were identified as independent risk factors of complications. CONCLUSION. Simultaneous operations, requiring economical resections are indicated in cases of synchronous metastases of rectal cancer in the liver. Simultaneous major R0 resections of the liver (till 70 % of livers parenchyma) done in specialized centers do not lead to increased complications, mortality rates and inpatient days.
ACTUAL CLINICAL APPROACH FOR COMPLICATED DIVERTICULAR DISEASE IN GENERAL SURGERY DEPARTMENT
Authors: Gibert B. K. , Matveev I. A. , Borodin N. A. , Zkhukov P. A. , Zakharova A. N. , Yanshina A. A.
Published: June 2019

AIM. To revise clinical approaches for patients with complicated diverticular disease used in daily clinical practice in tertiary referral regional center and its compliance with Federal Guidelines. PATIENTS AND METHODS. Twenty-three patients with inflammatory complications of diverticular disease were treated in a General Surgery Department of Regional Hospital of Tumen City in 2015-2016. Preoperative ultrasound was performed for 19 (82.6%) patients, CT - only for 4 (17.4%), laparoscopy - for 13 (56.5%). Seven of them had uncomplicated acute diverticulitis and were treated conservatively. Sixteen (69.6°%) patients underwent Hartmann procedure. Five of them had phlegmonous diverticulitis, 10 - sealed perforation and only 1 - free perforation with fecal peritonitis. RESULTS. According to recent studies in diverticular disease, conservative approach had positive prognosis in 15 of 16 operated patients. All procedures included extended resections with an aim to remove not only inflamed segment of bowel but segments with multiple diverticula as well. Distal part of sigmoid colon was included in specimen in all cases. CONCLUSION. None of recommendations of Federal Guidelines was used in daily clinical practice for patients with diverticular disease and indications for surgery were unreasonably extended in majority of cases. A juridical status of Federal Clinical Recommendations should be increased.
COMPARATIVE RESULTS OF PREOPERATIVE OIL CHEMOEMBOLIZATION OF REACTAL ARTERIES IN COMBINED TREATMENT OF RESECTABLE RECTAL CANCER
Authors: Zakharchenko A. A. , Popov A. V. , Vinnik Y. S. , Markelova N. M.
Published: June 2019

5-year results of combined treatment of 160 patients with respectable rectal cancer (TNM: IIab - IIIa-b) are analyzed. In 40 patients (study group)) neoadjuvant (72 h before surgery), endovascular oil Chemoembolization of the Rectal Arteries (RACHEL procedure) with a Lipiodol and 5-Fluorouraci was used. The results were compared with surgical treatment (control group 1, n=40) and preoperative radiotherapy methods (control group 2: 5 х 5 Gr, up to a Total Focal Dose of 25 Grandcontrolgroup3: High Dose radiotherapy with a Single Focal Dose of 13 Gr with program Endovascular Radio modification Metronidazole, for 40 patients). The preoperative RACHEL procedure in treatment of patients with resectable rectal cancer was effective with low local recurrence (2,6%) rate, at 5-year overall (89,7%) and disease -free survival (84,6%) and can compete with known preoperative radiotherapy in combined treatment of rectal cancer.
COMPARATIVE ANALYSIS OF OPEN AND TRANSANAL TOTAL MESORECTAL EXCISION FOR RECTAL CANCER
Authors: Shelygin Yu. A. , Chernyshov S. V. , Kazieva L. Yu. , Maynovskaya O. A. , Kashnikov V. N. , Rybakov E. G.
Published: June 2019

AIM: to evaluate results of transanal total mesorectal excision (TA TME) for rectal cancer. PATIENTS AND METHODS: Ninuty patients were included the prospective non-randomized study. Forty-five (50.0 %) of them underwent TA TME and 45 (50.0%) - conventional total mesorectal excision (TME). RESULTS: operation time was significantly higher in TA TME group: 276.4± 56.9 (190-400) minutes vs 188.0± 56.7 (100-310) minutes in open TME group (р=0.0001). The intraoperative complications rate was significantly higher in TA TME group: 7 (15.5 %) vs 1 (2.2 %) patient (р=0.05). No significant difference in postoperative morbidity was obtained: 18 (40.0%) in TA TME group vs 17 (37.7%) (р=1.0). Postoperative stay was lower in TATME group: 9 (7:14) vs 11 (10:14) days (р=0.04). Grade 2 specimen quality was detected significantly more often after TATME 26 (57.8 %) vs 15 (33.3 %) open TME (р=0.03), while Grade 3 specimens were more common after open procedure - 30 (66.7 %) vs 13 (28.9 %) TA TME group (р=0.0006). CONCLUSION: TA TME is a feasible procedure for rectal cancer patients. It demonstrated all benefits of minimally invasive technique, though learning curve is steep.
A NEW AGENT BOWEL CLEANSING BEFORE ENDOSCOPY - «COLOKIT»
Authors: Galyaev A. V. , Veselov V. V. , Romanov R. I. , Poltorykhina E. A. , Ozerova O. S.
Published: June 2019

AIM: to evaluate the efficacy, safety and drug tolerance of «Colokit» for bowel cleansing before colonoscopy.

PATIENTS AND METHODS: an open prospective non-randomised study of the quality of bowel cleansing was carried out in 30 patients (17 females, aged 26-72 years), who underwent diagnostic colonoscopy after using «Сolokit» (Mayoly Spindler, France) using two different regimes (recommended and alternative).

RESULTS: the quality of the bowel cleansing was significantly better in patients after «Colokit» use in recommended regime vs alternative regime. No difference in subjective assessment of patients’ comfort during bowel preparation was found in both regimes. CONCLUSION: the «Colokit» agent provides good preparation and patients’ comfort and can be recommended for the bowel cleansing before colonoscopy.
FIRST EXPERIENCE OF STRICTUROPLASTY IN A TEENAGER WITH COMPLICATED CROHN'S DISEASE (case report)
Authors: Shcherbakova O. V.
Published: June 2019

A rare clinical observation of spontaneous intestinal perforation into the free abdominal cavity in teenager with complicated Crohn's disease during steroids therapy is presented. The experience of exclusive enteral nutrition and the results of the first stricturoplasty in children are demonstrated.
Effects of Frequency of Irrigation on Dry-Season Furrow-Irrigated Maize and Peanut Production in the Rice-Growing Lowlands of the Lower Mekong Basin
Authors: Ballester Carlos , Vote Camilla , Hornbuckle John , Inthavong Thavone , Lim Vanndy , Oeurng Chantha , Quayle Wendy , Seng Vang , Sengxua Pheng , Sihathep Vorachith , Touch Veasna , Eberbach Philip
Published: June 2019

Incorporation of dry-season crops in the lowland production systems of the Lower Mekong Basin (LMB) may provide local smallholder farmers the opportunity to increase household cash income through diversification. However, water availability and lowland rice-growing soil characteristics often limit the yield potential of dry-season crops in rotation with wet-season rice. This work studied the effects of three frequencies of irrigation on the crop performance of dry-season furrow-irrigated maize (Zea mays Linnaeus) and peanut (Arachis hypogaea Linnaeus) grown on lowland rice-growing soils in terms of biomass, yield and water productivity (WP). In addition, the response of maize to two fertiliser rates was evaluated. The study was carried out in sites with typical lowland rice-growing soils located in Cambodia and Laos. Soil matric potential (Ψm) was monitored during the season at the centre of the beds and percentage of canopy cover, aboveground biomass (AGB), yield and WP were determined. The results showed that within the first weeks of furrow irrigation (~two weeks after emergence), Ψm dropped considerably (<−200 kPa) after all treatments at both sites, suggesting that water movement from the furrows to the centre of the beds was limited. Shorter frequency of irrigation led to significantly (p < 0.05) higher AGB and yield in maize but not in peanut. Fertiliser rates did not have a significant effect on maize. WP ranged from 0.84 kg m−3 to 1.42 kg m−3 for maize and from 0.27 kg m−3 to 0.49 kg m−3 for peanut with no significant differences among treatments. This work provides evidence of a lateral water movement limitation that is not well documented for the establishment of furrow-irrigated dry-season crop production in the lowlands of the LMB. Further research on methodologies that could help to overcome this limitation in these soils, such as the application of soil amendments or implementation of alternative irrigation systems, would be of great value.
Grape Rootstock Response to Salinity, Water and Combined Salinity and Water Stresses
Authors: Suarez Donald L. , Celis Nydia , Anderson Ray G. , Sandhu Devinder
Published: June 2019

Diminishing availability of non-saline water in arid and semiarid regions is of concern to all irrigated agricultural producers, including wine and grape producers. Grapes are not a salt tolerant crop and producers often face the choice of either limiting fresh water application, using alternative saline waters or a combination of both. We examined the salt tolerance and effect of restricted water application on three purported salt tolerant rootstocks grafted to Cabernet Sauvignon scion in a 4-year replicated field experiment. ANOVA indicated significant effects of salinity water stress and rootstock on fruit yields. The 140 Ruggeri scion was the top producer across all treatments including control, followed by Salt Creek, with St. George significantly less productive than 140 Ruggeri across all treatments. In terms of salt tolerance, Salt Creek and 140 Ruggeri were not statistically different but St. George was significantly less tolerant than Salt Creek. In terms of drought tolerance (relative yield), there were no statistical differences among rootstocks. Soil salinity profiles and soil moisture sensors indicated reduced water consumption under high salinity, thus no matric stress under 60% of optimal water application when high salt stress was present. The multiplicative stress model where salt and water stress are individually evaluated did not satisfactorily predict yield under combined salinity and reduced water application, likely due to decreased water consumption under saline conditions. Short term (one year) experiments underestimate salt damage to grape vines as salt tolerance decreased over the 4-year experiment.
Super Potent Bispecific Llama VHH Antibodies Neutralize HIV via a Combination of gp41 and gp120 Epitopes
Authors: Strokappe Nika M. , Hock Miriam , Rutten Lucy , Mccoy Laura E. , Back Jaap W. , Caillat Christophe , Haffke Matthias , Weiss Robin A. , Weissenhorn Winfried , Verrips Theo
Published: June 2019

Broad and potent neutralizing llama single domain antibodies (VHH) against HIV-1 targeting the CD4 binding site (CD4bs) have previously been isolated upon llama immunization. Here we describe the epitopes of three additional VHH groups selected from phage libraries. The 2E7 group binds to a new linear epitope in the first heptad repeat of gp41 that is only exposed in the fusion-intermediate conformation. The 1B5 group competes with co-receptor binding and the 1F10 group interacts with the crown of the gp120 V3 loop, occluded in native Env. We present biophysical and structural details on the 2E7 interaction with gp41. In order to further increase breadth and potency, we constructed bi-specific VHH. The combination of CD4bs VHH (J3/3E3) with 2E7 group VHH enhanced strain-specific neutralization with potencies up to 1400-fold higher than the mixture of the individual VHHs. Thus, these new bivalent VHH are potent new tools to develop therapeutic approaches or microbicide intervention.
Qualitative Analysis of Primary Care Provider Prescribing Decisions for Urinary Tract Infections
Authors: Grigoryan Larissa , Nash Susan , Zoorob Roger , Germanos George J. , Horsfield Matthew S. , Khan Fareed M. , Martin Lindsey , Trautner Barbara W.
Published: June 2019

Inappropriate choices and durations of therapy for urinary tract infections (UTI) are a common and widespread problem. In this qualitative study, we sought to understand why primary care providers (PCPs) choose certain antibiotics or durations of treatment and the sources of information they rely upon to guide antibiotic-prescribing decisions. We conducted semi-structured interviews with 18 PCPs in two family medicine clinics focused on antibiotic-prescribing decisions for UTIs. Our interview guide focused on awareness and familiarity with guidelines (knowledge), acceptance and outcome expectancy (attitudes), and external barriers. We followed a six-phase approach to thematic analysis, finding that many PCPs believe that fluoroquinolones achieve more a rapid and effective control of UTI symptoms than trimethoprim-sulfamethoxazole or nitrofurantoin. Most providers were unfamiliar with fosfomycin as a possible first-line agent for the treatment of acute cystitis. PCPs may be misled by advanced patient age, diabetes, and recurrent UTIs to make inappropriate choices for the treatment of acute cystitis. For support in clinical decision making, few providers relied on guidelines, preferring instead to have decision support embedded in the electronic medical record. Knowing the PCPs’ knowledge gaps and preferred sources of information will guide the development of a primary care-specific antibiotic stewardship intervention for acute cystitis.
Quantification of Berberine in Berberis vulgaris L. Root Extract and Its Curative and Prophylactic Role in Cisplatin-Induced In Vivo Toxicity and In Vitro Cytotoxicity
Authors: Ahmad Sarfraz , Hussain Amina , Hussain Aroosha , Abdullah Iskandar , Ali Muhammad Sajjad , Froeyen Matheus , Mirza Muhammad Usman
Published: June 2019

Cisplatin is amongst the most potent chemotherapeutic drugs with applications in more than 50% of cancer treatments, but dose-dependent side effects limit its usefulness. Berberis vulgaris L. (B. vulgaris) has a proven role in several therapeutic applications in the traditional medicinal system. High-performance liquid chromatography was used to quantify berberine, a potent alkaloid in the methanolic root extract of B. vulgaris (BvRE). Berberine chloride in BvRE was found to be 10.29% w/w. To assess the prophylactic and curative protective effects of BvRE on cisplatin-induced nephrotoxicity, hepatotoxicity, and hyperlipidemia, in vivo toxicity trials were carried out on 25 healthy male albino Wistar rats (130–180 g). Both prophylactic and curative trials included a single dose of cisplatin (4 mg/kg, i.p.) and nine doses of BvRE (500 mg/kg/day, orally). An array of marked toxicity effects appeared in response to cisplatin dosage evident by morphological condition, biochemical analysis of serum (urea, creatinine, total protein, alanine transaminase, aspartate transaminase, total cholesterol, and triglyceride), and organ tissue homogenates (malondialdehyde and catalase). Statistically-significant (p < 0.05) variations were observed in various parameters. Moreover, histological studies of liver and kidney tissues revealed that the protective effect of BvRE effectively minimized and reversed nephrotoxic, hepatotoxic, and hyperlipidemic effects caused by cisplatin in both prophylactic and curative groups with relatively promising ameliorative effects in the prophylactic regimen. The in vitro cell viability effect of cisplatin, BvRE, and their combination was determined on HeLa cells using the tetrazolium (MTT) assay. MTT clearly corroborated that HeLa cells appeared to be less sensitive to cisplatin and berberine individually, while the combination of both at the same concentrations resulted in growth inhibition of HeLa cells in a remarkable synergistic way. The present study validated the use of BvRE as a protective agent in combination therapy with cisplatin.
An Indirect Measurement Method for Gas Consumption of a Diaphragm Gas Meter Based on Gas Pressure Signal Detection
Authors: Han Zhao , Wang Xiaoli , Jiang Baochen , Chen Xiaopeng
Published: June 2019

At present, the remote meter reading problem for a large number of existing domestic diaphragm gas meters has not been reliably solved. The diaphragm gas meter uses a physical structure to measure gas consumption, so the main problem of remote meter reading is the digitization of gas consumption. Although it is possible to digitize the consumption data by modifying the internal structure of the gas meter or adding sensors, thereby realizing the function of remote meter reading, the modification process is complicated, the modification cost is high, and manual meter reading can only be used for the existing diaphragm gas meters. For this reason, this paper proposes an indirect measurement method of gas consumption based on gas pressure signal detection. The method can digitalize the metering results of the mechanical diaphragm gas meter and develop a state detection function by analyzing the pressure signal of the outlet of the meter without modifying the internal structure of a meter, thus addressing the key difficulties in the construction of a gas meter remote meter reading system. The experimental results show that this method has small calculation error and high reliability.
A Self-Consistent Quantum Field Theory for Random Lasing
Authors: Lubatsch Andreas , Frank Regine
Published: June 2019

The spatial formation of coherent random laser modes in strongly scattering disordered random media is a central feature in the understanding of the physics of random lasers. We derive a quantum field theoretical method for random lasing in disordered samples of complex amplifying Mie resonators which is able to provide self-consistently and free of any fit parameter the full set of transport characteristics at and above the laser phase transition. The coherence length and the correlation volume respectively is derived as an experimentally measurable scale of the phase transition at the laser threshold. We find that the process of stimulated emission in extended disordered arrangements of active Mie resonators is ultimately connected to time-reversal symmetric multiple scattering in the sense of photonic transport while the diffusion coefficient is finite. A power law is found for the random laser mode diameters in stationary state with increasing pump intensity.
A Novel Emergency Braking Control Strategy for Dual-Motor Electric Drive Tracked Vehicles Based on Regenerative Braking
Authors: Chen Zhaomeng , Zhou Xiaojun , Wang Zhe , Li Yaoheng , Hu Bo
Published: June 2019

Dual-motor electric drive tracked vehicles (DDTVs) have drawn much attention in the trends of hybridization and electrification for tracked vehicles. Their transmission chains differ significantly from the traditional ones. Due to the complication and slug of a traditional tracked vehicle braking system, as well as the difference of track-ground with tire-road, research of antilock braking control of tracked vehicles is rather lacking. With the application of permanent magnet synchronous motors (PMSMs), applying an advanced braking control strategy becomes practical. This paper develops a novel emergency braking control strategy using a sliding mode slip ratio controller and a rule-based braking torque allocating method. Simulations are conducted under various track-ground conditions for comparing the control performance of the proposed strategy with three other strategies including the full braking strategy, traditional antilock braking strategy, as well as sliding mode slip ratio strategy without the use of motors. For an initial speed of 80 km/h, simulation results show that the proposed control strategy performs the best among all strategies mentioned above. Several hardware-in-the-loop (HIL) experiments are conducted under the same track-ground conditions as the ones in the simulations. The experiment results verified the validity of the proposed emergency braking control strategy.
An Open-Loop Receiver Architecture for Monitoring of Ionospheric Scintillations by Means of GNSS Signals
Authors: Linty Nicola , Dovis Fabio
Published: June 2019

The quality of positioning services based on Global Navigation Satellite Systems (GNSS) is improving at a fast pace, driven by the strict requirements of a plethora of new applications on accuracy, precision and reliability of the services. Nevertheless, ionospheric errors still bound the achievable performance and better mitigation techniques must be devised. In particular, the harmful effect due to non-uniform distribution of the electron density that causes amplitude and phase variation of the GNSS signal, usually named as scintillation effects. For many high-accuracy applications, this is a threat to accuracy and reliability, and the presence of scintillation effect needs to be constantly monitored. To this purpose, traditional receivers employ closed-loop tracking architectures. In this paper, we investigate an alternative architecture and a related metric based on the statistical processing of the received signal, after a code-wipe off and a noise reduction phase. The new metric is based on the analysis of the statistical features of the conditioned signal, and it brings the same information of the S 4 index, normally estimated by means of closed-loop receivers. This new metric can be obtained at a higher rate as well as in the case of strong scintillations when a closed-loop receiver would fail the tracking of the GNSS signals.
A Review on the Thermal Hazards of the Lithium-Ion Battery and the Corresponding Countermeasures
Authors: Ouyang Dongxu , Chen Mingyi , Huang Que , Weng Jingwen , Wang Zhi , Wang Jian
Published: June 2019

As one of the most promising new energy sources, the lithium-ion battery (LIB) and its associated safety concerns have attracted great research interest. Herein, a comprehensive review on the thermal hazards of LIBs and the corresponding countermeasures is provided. In general, the thermal hazards of the LIB can be caused or aggravated by several factors including physical, electrical and thermal factors, manufacturing defect and even battery aging. Due to the activity and combustibility of traditional battery components, they usually possess a relatively high thermal hazard and a series of side reactions between electrodes and electrolytes may occur under abusive conditions, which would further lead to the thermal failure of LIBs. Besides, the thermal hazards generally manifest as the thermal runaway behaviors such as high-temperature, ejection, combustion, explosion and toxic gases for a single battery, and it can even evolve to thermal failure propagation within a battery pack. To decrease these hazards, some countermeasures are reviewed including the application of safety devices, fire-retardant additives, battery management systems, hazard warnings and firefighting should a hazard occur.
High-Speed VCSEL-Based Transceiver for 200 GbE Short-Reach Intra-Datacenter Optical Interconnects
Authors: Kanakis Giannis , Iliadis Nikos , Soenen Wouter , Moeneclaey Bart , Argyris Nikolaos , Kalavrouziotis Dimitrios , Spiga Silvia , Bakopoulos Paraskevas , Avramopoulos Hercules
Published: June 2019

The soaring demand for higher speeds in datacenters to address the relentless growth of the global IP traffic places optical interconnects in the spotlight. In this manuscript, we present a high-speed optical transceiver for intra-datacenter connectivity. The transceiver is based on single-mode, single-polarization high-speed vertical-cavity surface-emitting lasers (VCSELs), a VCSEL driver chip, and a linear receiver. Following a step-by-step approach, we present the architectures, assembly processes, and experimental results from the different modules. More specifically, we demonstrate (1) a data transmission experiment at 80 Gb/s using PAM-4 (four-level Pulse Amplitude Modulation) modulation for a reach of up to 500 m by employing a single-mode VCSEL module, and (2) a full-link experiment proving up to 64 Gb/s per lane capacity using PAM-4 signaling of the VCSEL-based optical transceiver test vehicles in back-to-back configuration and up to 56 Gb/s for 500 m and 2 km transmission distances. The acquired experimental results verify the suitability of the optical transceiver for intra-datacenter interconnects’ applications.
Adaptive Fuzzy-Based Fault-Tolerant Control of a Continuum Robotic System for Maxillary Sinus Surgery
Authors: Piltan Farzin , Kim Cheol-Hong , Kim Jong-Myon
Published: June 2019

Continuum robots represent a class of highly sensitive, multiple-degrees-of-freedom robots that are biologically inspired. Because of their flexibility and accuracy, these robots can be used in maxillary sinus surgery. The design of an effective procedure with high accuracy, reliability, robust fault diagnosis, and fault-tolerant control for a surgical robot for the sinus is necessary to maintain the high performance and safety necessary for surgery on the maxillary sinus. Thus, a robust adaptive hybrid observation method using an adaptive, fuzzy auto regressive with exogenous input (ARX) Laguerre Takagi–Sugeno (T–S) fuzzy robust feedback linearization observer for a surgical robot is presented. To address the issues of system modeling, the fuzzy ARX-Laguerre technique is represented. In addition, a T–S fuzzy robust feedback linearization observer is applied to a fuzzy ARX-Laguerre to improve the accuracy of fault estimation, reliability, and robustness for the surgical robot in the presence of uncertainties. For fault-tolerant control in the presence of uncertainties and unknown conditions, an adaptive fuzzy observation-based feedback linearization technique is presented. The effectiveness of the proposed algorithm is tested with simulations. Experimental results show that the proposed method reduces the average position error from 35 mm to 2.45 mm in the presence of faults.
Experimental Investigation of Micropile Stiffness Affecting the Underpinning of an Existing Foundation
Authors: Wang Chengcan , Han Jin-Tae , Jang Young-Eun
Published: June 2019

Underpinning in an existing foundation with piles is commonly used to improve their load-bearing capacity to allow vertical extension works. This study evaluated the effect of the piles’ stiffness on the load-sharing behavior of existing and underpinning piles during the vertical extension of existing buildings. A series of 1 g model tests, all with a scale factor of 1/20, was used to compare the underpinning performance of micropiles of varying stiffness. The performance was evaluated in terms of total settlement reduction and load sharing capacity. The results showed that the underpinning performance improved with the increase of underpinning pile stiffness. The ratio of carried loads of the underpinning pile to the existing pile increased linearly with its increasing stiffness (as expressed as a ratio relative to the stiffness of the existing pile).
Mechanical Behavior of a Double-Column Self-Centering Pier Fused with Shear Links
Authors: Xu Liangjin , Lu Xinzheng , Zou Qiaoshan , Ye Lieping , Di Jin
Published: June 2019

A double-column self-centering pier fused with shear links is a novel structure developed to reduce residual deformation and facilitate post-earthquake repair. With this novel structure, the seismic resilience of bridges can be improved, and the reliability of lifeline infrastructure can be ensured. This paper presents the proposed pier configuration and investigates the mechanical behavior of the pier. A simplified finite element model is established to develop the lateral force-displacement relationship under cyclic loading. Additionally, a theoretical model based on the matrix displacement method and the virtual work principle is proposed to calculate the lateral force-displacement skeleton curve. The rationality and reliability of the theoretical model are validated by the satisfactory agreement observed between the numerical and theoretical results. Furthermore, a series of parametric analyses are conducted to discuss the effects of key parameters. The outcomes of this work can serve as a reference for further development of the design method for the innovated pier.
Evolution of b-Value and Fractal Dimension of Acoustic Emission Events During Shear Rupture of an Immature Fault in Granite
Authors: Lei Xinglin
Published: June 2019

The present study investigated the evolutions of b-value and fractal dimension of acoustic emission (AE) events during shear rupture of a naturally-created rough fracture in a granite specimen under triaxial compression. Acoustic emission signals were monitored by 16 sensors mounted directly on the surface of the specimen, and AE waveforms were sampled at 16 bits and 25 MHz. Reliable hypocenters were determined using P-wave arrival times picked up from the waveforms. Acoustic emission magnitude was determined from the maximum amplitude monitored by two peak detectors, which have a relative magnitude range of 0 to 2.75. A three-dimensional X-ray computed tomography scan was performed after the test to explore the fracture geometry. Acoustic emission activity was initiated during hydrostatic compression. With increasing differential stress, AEs demonstrated an increasing event rate, a decrease (from approximately 1.8 to 1.6) with a subsequent precursory increase (from 1.6 to 1.8) in fractal dimension, a quick decrease in b-value (from 1.0 to approximately 0.5), and a quick increase in fractal dimension (from 1.8 to 2.0). The exponentially increasing event rate, gradually decreasing b-value, and slowly increasing fractal dimension may be an intermediate-term indication of fault reactivation. In contrast, a progressively increasing event rate, a rapid drop in b-value, and a rapid increase in fractal dimension may facilitate short-term prediction of large events, which reflect the rupture of large patches. Acoustic emission hypocenters were clustered on the entire fracture surface. The present study sheds some light on detecting early signs of fault reactivation by monitoring injection-induced seismicity in areas with faults of different maturity.
Psychophysiological Alteration After Virtual Reality Experiences Using Smartphone-Assisted Head Mount Displays: An EEG-Based Source Localization Study
Authors: Kim Jeong-Youn , Son Jae-Beom , Leem Hyun-Sung , Lee Seung-Hwan
Published: June 2019

Brain functional changes could be observed in people after an experience of virtual reality (VR). The present study investigated cyber sickness and changes of brain regional activity using electroencephalogram (EEG)-based source localization, before and after a VR experience involving a smartphone-assisted head mount display. Thirty participants (mean age = 25 years old) were recruited. All were physically healthy and had no ophthalmological diseases. Their corrected vision was better than 20/20. Resting state EEG and the simulator sickness questionnaire (SSQ) were measured before and after the VR experience. Source activity of each frequency band was calculated using the sLORETA program. After the VR experience, the SSQ total score and sub scores (nausea, oculomotor symptoms, and disorientation) were significantly increased, and brain source activations were significantly increased: alpha1 activity in the cuneus and alpha2 activity in the cuneus and posterior cingulate gyrus (PCG). The change of SSQ score (after–before) showed significant negative correlation with the change of PCG activation (after–before) in the alpha2 band. The study demonstrated increased cyber sickness and increased alpha band power in the cuneus and PCG after the VR experience. Reduced PCG activation in alpha band may be associated with the symptom severity of cyber sickness.
Ground Improvement Using Dynamic Compaction in Sabkha Deposit
Authors: Moon Joon-Shik , Jung Hyuk Sang , Lee Sungjune , Kang Su-Tae
Published: June 2019

The sabkha soil spreads extensively in the Arabian Gulf Coast region. Sabkha is known as a geotechnically problematic soil because of its loose density, soft consistency, high salinity and water content, and occurrence of fine sands and clays. It is generally highly compressible and requires ground improvement for highway and railway construction. The purpose of this study is to provide a guideline for dynamic compaction to improve the bearing capacity of the coastal sabkha deposit. The ground behavior during dynamic compaction was evaluated for various compaction energy conditions using numerical analysis, and field dynamic compaction tests were also performed and compared with the numerical analysis results. It was found that the bearing capacity of sabkha deposit can be effectively improved by dynamic compaction. However, care must be taken to ensure that excessive porewater pressure is sufficiently dissipated during the application of dynamic compaction because the permeability is pretty low due to the high salt content in groundwater in the sabkha area.
Isolation and Characterization of Three Chalcone Synthase Genes in Pecan (Carya illinoinensis)
Authors: Zhang Chengcai , Yao Xiaohua , Ren Huadong , Wang Kailiang , Chang Jun
Published: June 2019

Phenolics are a group of important plant secondary metabolites that have been proven to possess remarkable antioxidant activity and to be beneficial for human health. Pecan nuts are an excellent source of dietary phenolics. In recent years, many studies have focused on the separation and biochemical analysis of pecan phenolics, but the molecular mechanisms of phenolic metabolism in pecans have not been fully elucidated, which significantly hinders quality breeding research for this plant. Chalcone synthase (CHS) plays crucial roles in phenolic biosynthesis. In this study, three Carya illinoinensis CHSs (CiCHS1, CiCHS2, and CiCHS3), were isolated and analyzed. CiCHS2 and CiCHS3 present high expression levels in different tissues, and they are also highly expressed at the initial developmental stages of kernels in three pecan genotypes. A correlation analysis was performed between the phenolic content and CHSs expression values during kernel development. The results indicated that the expression variations of CiCHS2 and CiCHS3 are significantly related to changes in total phenolic content. Therefore, CiCHSs play crucial roles in phenolic components synthesis in pecan. We believe that the isolation of CiCHSs is helpful for understanding phenolic metabolism in C. illinoinensis, which will improve quality breeding and resistance breeding studies in this plant.
Synthesis and Biological Evaluation of Novel Selenyl and Sulfur-l-Dopa Derivatives as Potential Anti-Parkinson’s Disease Agents
Authors: Di Stefano Antonio , Marinelli Lisa , Eusepi Piera , Ciulla Michele , Fulle Stefania , Di Filippo Ester Sara , Magliulo Laura , Di Biase Giuseppe , Cacciatore Ivana
Published: June 2019

Parkinson’s disease (PD) is a neurodegenerative disorder characterized by loss of dopaminergic neurons at level of substantia nigra pars compacta. To date, there is no cure for this pathology, except for some drugs able to alleviate the symptoms of PD. In this paper we report the synthesis and biological evaluation of novel sulfur- and selenyl-l-Dopa (LD) derivatives (SP1–6) obtained through the amide junction between the amino group of LD and carboxylic moiety of sulfur- and selenyl-organic compounds, which are commercially available. Biological activity was evaluated on human undifferentiated and retinoic acid/phorbol myristyl acetate (RA/PMA)-differentiated SY-SH5Y neuroblastoma cell line using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Antioxidant activity against oxidative stress was measured using nitroblue tetrazolium (NBT) and 2’,7’-dichlorodihydrofluorescein diacetate (H2DCFDA) assays. Finally, physico-chemical characterization and plasma stability studies of SP1–6 were also performed. Biological data revealed that SP6 has a significant protective action against the neurotoxic action of 6-hydroxydopamine (6-OHDA) and H2O2 in a RA/PMA-differentiated SY-SH5Y neuroblastoma cell line that proved to be an effective antioxidant and protective compound. SP6, endowed with a lipophilic nature, low molecular weight, and plasma stability, can easily cross biological membranes via passive diffusion such as through the blood–brain barrier. SP6 has great potential for developing novel pharmacological approach for neurodegenerative diseases, such as PD. Further studies will help define its exact antioxidant mechanism and determine whether the neuroprotective action is mediated or modulated by glutathione peroxidase (GPx).
Evidence for Contamination of Silica Microparticles in Advanced Platelet-Rich Fibrin Matrices Prepared Using Silica-Coated Plastic Tubes
Authors: Tsujino Tetsuhiro , Takahashi Akira , Yamaguchi Sadahiro , Watanabe Taisuke , Isobe Kazushige , Kitamura Yutaka , Tanaka Takaaki , Nakata Koh , Kawase Tomoyuki
Published: June 2019

Platelet-rich fibrin (PRF) therapy has been widely applied in regenerative dentistry, and PRF preparation has been optimized to efficiently form fibrin clots using plain glass tubes. Currently, a shortage of commercially available glass tubes has forced PRF users to utilize silica-coated plastic tubes. However, most plastic tubes are approved by regulatory authorities only for diagnostic use and remain to be approved for PRF therapy. To clarify this issue, we quantified silica microparticles incorporated into the PRF matrix. Blood samples were collected into three different brands of silica-containing plastic tubes and were immediately centrifuged following the protocol for advanced-PRF (A-PRF). Advanced-PRF-like matrices were examined using a scanning electron microscope (SEM), and silica microparticles were quantified using a spectrophotometer. Each brand used silica microparticles of specific size and appearance. Regardless of tube brands and individual donors, significant, but not accidental, levels of silica microparticles were found to be incorporated into the A-PRF-like matrix, which will be consequently incorporated into the implantation sites. Presently, from the increasing data for cytotoxicity of amorphous silica, we cannot exclude the possibility that such A-PRF-like matrices negatively influence tissue regeneration through induction of inflammation. Further investigation should be performed to clarify such potential risks.
Factors that Promote Resilience in Homeless Children and Adolescents in Ghana: A Qualitative Study
Authors: Oppong Asante Kwaku
Published: June 2019

Several studies conducted on street youth have focused on causes of homelessness, their engagement in risky sexual behaviours and the prevalence of STIs, including HIV/AIDS. Although homeless youth are considered resilient, sparse literature exists on factors that promote resilience in this vulnerable group. Using a qualitative approach, semi-structured interviews were conducted with 16 purposively selected homeless children and youth (with a mean age of 14 years) from the Central Business District of Accra, Ghana. Thematic analysis was used to analyse the data. Findings showed that a strong religious belief, sense of humour, engagement in meaningful social interactive activities, reciprocal friendship, adherence to cultural norms and support from community-based organizations were identified as factors that help homeless youth cope with the multiple challenges of street life. Strengthening such protective factors could help ameliorate the impact of adverse conditions of these street youth.
Reducing the Seismic Vulnerability of Existing Buildings: Assessment and Retrofit
Authors: Ferreira Tiago Miguel , Mendes Nuno , Silva Rui
Published: June 2019

Devastating seismic events occurring all over the world keep raising the awareness of the scientific, technical and political communities to the need of identifying assets at risk and developing more effective and cost-efficient seismic risk mitigation strategies [...]