Preparation and characterization of polyhydroxybutyrate/polycaprolactone/Mg-Al layered double hydroxide nanocomposites

Anionic clay Mg-Al Layered double hydroxide (Mg-Al LDHs) of Mg/Al-NO3 - with M2+:M3+ (3:1) ratio was synthesized by co-precipitation method from nitrate salt solutions were used with continuous agitation at constant pH 9. Beside, modification of nitrate anions by stearate anions between the LDH layers had carried out through ion exchange reaction. Polyhydroxybutyrate (PHB)/Polycaprolactone (PCL)/stearate Mg-Al Layered Double Hydroxide (LDH) nanocomposites were prepared via solution casting intercalation method. FT-IR spectra showed the presence of carboxylic acid (COOH) group indicates that stearate anions were successfully replacing the nitrate anions in the interlayer Mg-Al LDH. The XRD results showed that increasing basal spacing from 8.66 to 32.97 Å in modified stearate Mg-Al LDH. Additional of 1.0 wt % stearate Mg-Al LDH resulting higher basal spacing where polymer chain intercalated into interlayer LDH and TEM results revealed that the 1.0 wt % stearate Mg-Al LDH layers are homogeneously distributed in the PHB/PCL polymer blends matrix. TGA characterization proven that 80PHB/20PCL/1stearate Mg-Al LDH has lower weight loss and higher thermal stability. Enhancement in 300% elongation at break and 66% tensile strength in the presence of 1.0 wt % of the stearate Mg-Al LDH as compare with PHB/PCL blends. Scanning electron microscopy (SEM) proved that clay improves compatibility between polymer matrix and the best ratio 80PHB/20PCL/1stearate Mg-Al LDH surface was well dispersed and stretched before it breaks

An investigation into customer perception and behaviour through social media research – an empirical study of the United Airline overbooking crisis

Airlines have been adopting yield management to optimise the perishable seat control problem and overbooking is a common strategy. This study outlines the connections between yield management, crises, and crisis communication. Using big data captured on a social media platform, this study aims to combine traditional yield management with emerging social big data analytics. As part of this, we use the twitter data on the 2017 United Airline (UA) to analyse the overbooking crisis. Our findings shed light on the importance of a more effective orchestration of yield management to avoid the escalation of crises during crisis communication phases

Tokyo Guidelines 2018 management bundles for acute cholangitis and cholecystitis

Management bundles that define items or procedures strongly recommended in clinical practice have been used in many guidelines in recent years. Application of these bundles facilitates the adaptation of guidelines and helps improve the prognosis of target diseases. In Tokyo Guidelines 2013 (TG13), we proposed management bundles for acute cholangitis and cholecystitis. Here, in Tokyo Guidelines 2018 (TG18), we redefine the management bundles for acute cholangitis and cholecystitis. Critical parts of the bundles in TG18 include the diagnostic process, severity assessment, transfer of patients if necessary, and therapeutic approach at each time point. Observance of these items and procedures should improve the prognosis of acute cholangitis and cholecystitis. Studies are now needed to evaluate the dissemination of these TG18 bundles and their effectiveness. Free full articles and mobile app of TG18 are available at: . Related clinical questions and references are also include

The mediating effect of motivations between psychiatric distress and gaming disorder among esport gamers and recreational gamers

Research examining the relationship between gaming disorder, gaming motivations, and mental health is increasing, but the types of gaming use, such as recreational gaming and esports are not commonly distinguished. The present study compared recreational gamers and esport gamers (N = 4284) on a number of variables including game time, gaming motivations, severity of gaming disorder, and psychiatric symptoms. Additionally, the mediating effect of gaming motivations among esport and recreational gamers between psychiatric distress and problematic gaming was examined. Results showed that esport gamers spent significantly more time playing video games both on weekdays and weekend days than recreational gamers. Moreover, esport gamers had higher scores on social, competition, and skill development gaming motivations than recreational gamers. The mediation model demonstrated a significant positive direct and significant mediated effect via escapism (i.e., gaming excessively to avoid real life problems) between the higher levels of psychiatric distress and gaming disorder. However, esport and recreational gamers showed no significant differences in the model. The escapism motive appeared to be the common predictor of problematic gaming among both esport and recreational gamers. Future studies should focus on exploring escapism's mechanism in different subgroups of gamers in relation to problematic gaming to help the development of prevention, intervention, and treatment programs

Tokyo Guidelines 2018: initial management of acute biliary infection and flowchart for acute cholangitis

The initial management of patients with suspected acute biliary infection starts with the measurement of vital signs to assess whether or not the situation is urgent. If the case is judged to be urgent, initial medical treatment should be started immediately including respiratory/circulatory management if required, without waiting for a definitive diagnosis. The patient's medical history is then taken; an abdominal examination is performed; blood tests, urinalysis, and diagnostic imaging are carried out; and a diagnosis is made using the diagnostic criteria for cholangitis/cholecystitis. Once the diagnosis has been confirmed, initial medical treatment should be started immediately, severity should be assessed according to the severity grading criteria for acute cholangitis/cholecystitis, and the patient's general status should be evaluated. For mild acute cholangitis, in most cases initial treatment including antibiotics is sufficient, and most patients do not require biliary drainage. However, biliary drainage should be considered if a patient does not respond to initial treatment. For moderate acute cholangitis, early endoscopic or percutaneous transhepatic biliary drainage is indicated. If the underlying etiology requires treatment, this should be provided after the patient's general condition has improved; endoscopic sphincterotomy and subsequent choledocholithotomy may be performed together with biliary drainage. For severe acute cholangitis, appropriate respiratory/circulatory management is required. Biliary drainage should be performed as soon as possible after the patient's general condition has been improved by initial treatment and respiratory/circulatory management. Free full articles and mobile app of TG18 are available at: http://www.jshbps.jp/modules/en/index.php?content_id=47 . Related clinical questions and references are also include

Tokyo Guidelines 2018 diagnostic criteria and severity grading of acute cholecystitis (with videos)

The Tokyo Guidelines 2013 (TG13) for acute cholangitis and cholecystitis were globally disseminated and various clinical studies about the management of acute cholecystitis were reported by many researchers and clinicians from all over the world. The 1st edition of the Tokyo Guidelines 2007 (TG07) was revised in 2013. According to that revision, the TG13 diagnostic criteria of acute cholecystitis provided better specificity and higher diagnostic accuracy. Thorough our literature search about diagnostic criteria for acute cholecystitis, new and strong evidence that had been released from 2013 to 2017 was not found with serious and important issues about using TG13 diagnostic criteria of acute cholecystitis. On the other hand, the TG13 severity grading for acute cholecystitis has been validated in numerous studies. As a result of these reviews, the TG13 severity grading for acute cholecystitis was significantly associated with parameters including 30-day overall mortality, length of hospital stay, conversion rates to open surgery, and medical costs. In terms of severity assessment, breakthrough and intensive literature for revising severity grading was not reported. Consequently, TG13 diagnostic criteria and severity grading were judged from numerous validation studies as useful indicators in clinical practice and adopted as TG18/TG13 diagnostic criteria and severity grading of acute cholecystitis without any modification. Free full articles and mobile app of TG18 are available at: http://www.jshbps.jp/modules/en/index.php?content_id=47. Related clinical questions and references are also include

Delphi consensus on bile duct injuries during laparoscopic cholecystectomy:An evolutionary cul-de-sac or the birth pangs of a new technical framework?

Bile duct injury (BDI) during laparoscopic cholecystectomy remains a serious iatrogenic surgical complication. BDI most often occurs as a result of misidentification of the anatomy; however, clinical evidence on its precise mechanism and surgeons' perceptions is scarce. Surgeons from Japan, Korea, Taiwan, and the USA, etc. (n=614) participated in a questionnaire regarding their BDI experience and near-misses; and perceptions on landmarks, intraoperative findings, and surgical techniques. Respondents voted for a Delphi process and graded each item on a five-point scale. The consensus was built when 80% of overall responses were 4 or 5. Response rates for the first- and second-round Delphi were 60.6% and 74.9%, respectively. Misidentification of local anatomy accounted for 76.2% of BDI. Final consensus was reached on: (1) Effective retraction of the gallbladder, (2) Always obtaining critical view of safety, and (3) Avoiding excessive use of electrocautery/clipping as vital procedures; and (4) Calot's triangle area and (5) Critical view of safety as important landmarks. For (6) Impacted gallstone and (7) Severe fibrosis/scarring in Calot's triangle, bail-out procedures may be indicated. A consensus was reached among expert surgeons on relevant landmarks and intraoperative findings and appropriate surgical techniques to avoid BD

TG18 management strategies for gallbladder drainage in patients with acute cholecystitis: Updated Tokyo Guidelines 2018 (with videos)

Since the publication of the Tokyo Guidelines in 2007 and their revision in 2013, appropriate management for acute cholecystitis has been more clearly established. Since the last revision, several manuscripts, especially for alternative endoscopic techniques, have been reported; therefore, additional evaluation and refinement of the 2013 Guidelines is required. We describe a standard drainage method for surgically high-risk patients with acute cholecystitis and the latest developed endoscopic gallbladder drainage techniques described in the updated Tokyo Guidelines 2018 (TG18). Our study confirmed that percutaneous transhepatic gallbladder drainage should be considered the first alternative to surgical intervention in surgically high-risk patients with acute cholecystitis. Also, endoscopic transpapillary gallbladder drainage or endoscopic ultrasound-guided gallbladder drainage can be considered in high-volume institutes by skilled endoscopists. In the endoscopic transpapillary approach, either endoscopic naso-gallbladder drainage or gallbladder stenting can be considered for gallbladder drainage. We also introduce special techniques and the latest outcomes of endoscopic ultrasound-guided gallbladder drainage studies. Free full articles and mobile app of TG18 are available at: . Related clinical questions and references are also include

Parallel robot for 3D additive manufacturing

Fused Deposition Modelling (FDM) 3D printing technology was integrated with a 6 degree of freedom (DOF) delta robot to form the prototype for this project. It is an improvement from conventional 3-DOF FDM 3D printer which were constructed based on 3 axes (x, y and z) configuration that limit the printing process. On the flip side, parallel robot such as delta robot are reputable for high speed maneuverability and the degree of freedom in its motion path. These would significantly improve the process capability and the flexibility in the motion path of the print head during the printing process. One of the core objective for this project was to resolve parallelism issue that arose in this prototype. Another objective was to calibrate the extruder and obtain parameters that would give best printing. The focus of this report would be on delta robot motion controls, extrusion calibration and design of experiment to obtain ideal parameters. Kinematics equations were used to implement velocity control through changing the kinematic variables of the joints. These kinematics variables changes with respect to time to allow proper coordination among the 6 axes in the prototype. With synchronous coordination between these axes, parallel motion at the end effector of the prototype was achieved. Effectiveness of this changes in the controls were proved by conducting linearity test to draw shapes on a piece of paper with a pen attached at the end effector. Faults found in the extrusion process were resolved by identifying the root causes and making necessary component replacement. In-depth studies for the extrusion process were conducted and analyzed during troubleshooting of these faults. The effect of the extrusion flow rate and temperature on the printing quality and productivity was investigated by 2K design experiment. It was found that the best setting is achieved with extrusion flow rate of 4900 mm/min at 230ºC.Bachelor of Engineering (Mechanical Engineering

Understanding the role of clan associations in social integration : a study of PRC Chinese undergraduates and postgraduates in Singapore

With an increasing number of new citizens from China in Singapore over the years, Chinese clan associations are tasked to resume their role to help these new citizens integrate into Singapore’s multiracial society. This paper seeks to explore the challenges faced by the clan associations from the views of PRC Chinese undergraduates and postgraduates in Singapore. Through in-depth interviews to find out their views and experiences, the study will examine the dialect diversity resulting from familiarity with native languages and stigma arising from being minority in a more dominant majority setting. Motivations of joining clan associations for social capital and identity will be discussed. The study will conclude with how new media provides an alternative mean of social integration for the immigrants.Bachelor of Art