Managing disruptions in the multi-depot vehicle scheduling problem

We consider two types of disruptions arising in the multi-depot vehicle scheduling; the delays and the extra trips. These disruptions may or may not occur during operations, and hence they need to be indirectly incorporated into the planned schedule by anticipating their likely occurence times. We present a unique recovery method to handle these potential disruptions. Our method is based on partially swapping two planned routes in such a way that the effect on the planned schedule is minimal, if these disruptions are actually realized. The mathematical programming model for the multi-depot vehicle scheduling problem, which incorporates these robustness considerations, possesses a special structure. This special structure causes the conventional column generation method fall short as the resulting problem grows also row-wise when columns are generated. We design an exact simultaneous column-and-row generation algorithm to find a valid lower-bound. The novel aspect of this algorithm is the pricing subproblem, which generates pairs of routes that form recovery solutions. Compromising on exactness, we modify this algorithm in order to enable it to solve practical-sized instances efficiently. This heuristic algorithm is shown to provide very tight bounds on the randomly generated instances in a short computation time

Synthesis and properties of waterborne few-layer graphene oxide/poly (MMA-co-BuA) nanocomposites by in situ emulsion polymerization

Waterborne few-layer graphene oxide/poly(methyl methacrylate-co-butyl acrylate), FLGO/poly(MMA-co-BuA), nanocomposites were synthesized by in situ emulsion polymerization. The FLGO nanosheets used in this study was prepared by modified Hummers method and followed by an exfoliation process. The obtained FLGO and both latex and film forms of the nanocomposites were characterized in detail. It was found that the interactions between FLGO and copolymer matrix, and therefore the nanocomposite properties including colloidal, morphological, thermal and mechanical were directly dependent on the amount of FLGO in the composite composition. With the addition of 1% FLGO by weight (relative to the monomer), hydrodynamic diameters of the polymer particles in latex increased from 39.7 nm to 92.0 nm and moreover zeta potential value of this nanocomposite latex reached to -85 mV. Also, the nanocomposite film of this nanocomposite showed significant improvements in glass transition temperature (T-g), thermal degradation temperatures and Young's modulus values, comparing with other nanocomposites. The analysis results confirmed that the FLGO was chemically interacted with the poly(MMA-co-BuA), and also finely dispersed in the matrix

Temozolomide increases heat shock proteins in extracellular vesicles released from glioblastoma cells

Background Glioblastoma (GBM) is the most malignant and the fastest-progressing type of primary brain tumours. Temozolomide (TMZ) is a chemotherapeutic drug for the treatment of GBM. Extracellular vesicles (EVs) have been recently confirmed to have a substantial role in the GBM, and their contents released from GBM cells have been considered a target for treatment. The purpose of this study is to evaluate the impact of TMZ on heat shock proteins (HSPs) derived from EVs originated from GBM cell lines (U87-MG and LN229) and the significance of EVs in response to chemotherapy in GBM. Methods and results NTA, ELISA, and immunoblotting were used to characterization studies of EVs and results showed that U87-MG cells released many EVs compared to LN229 cells. The effect of TMZ treatments on HSPs expression levels were assessed with immunoblotting and was found to be led to increases in HSF-1, Hsp90, Hsp70, Hsp60 and Hsp27 expression in GBM cells and their EV contents, which these increases are related to therapeutic resistance. What is more, in Real-time PCR studies showing which signalling pathways might be associated with these increases, it was observed that TMZ triggered the expression of RAD51 and MDM2 genes in cells and EV contents. More strikingly, we discover a correlation between EV and parental cells in regard of mRNA and protein level in both cell lines as a result of TMZ treatment. Conclusions Our data suggest of EVs in the treatment of GBM may have potential biomarkers that can be used to investigate the treatment response

Therapeutic Drugs and Natural Products: The Effect of Suppressing Heat Shock Proteins (Hsp) in Brain Tumors

Brain tumors are common in the population, and approximately 17,000 new patients are diagnosed every year. Although there are advancements in conventional treatment, including surgery, radiotherapy and chemotherapy, they have limited effectiveness for the patients with brain tumors. However, with recent developments of tumor biology, novel approaches discovering new agents or their combinations have been proposed. Heat shock proteins (HSP) serve as molecular chaperones and they play a prominent role in protein homeostasis. Expression level of HSP enhance under the stressful conditions and they protect the cells by assisting of protein folding. In addition, HSP have attracted a great interest as a potential anticancer target and the development of HSP inhibitors demonstrating treatment is promising for cancer. Several therapeutic drugs and natural products that target signaling pathways associated with HSP are being developed and the efficacy of these agents in brain tumors is investigated. Consequently, our chapter puts emphasis on application of HSP in the treatment of brain tumors and the potential of therapeutic drugs and/or natural products in these tumors. It is hoped that approaches discussed in this chapter will overcome the existing limitations in the treatment with brain tumors and lead to a better prognosis for the patients

Remembering the Basics: A Patient with Sickle Cell Disease and Proteinuria

Patients with sickle cell disease (SCD) tend to develop many renal abnormalities, including concentration defect, renal papillary necrosis, and glomerulopathy that often presents with proteinuria. We report a case of a patient who presented with sickle cell crisis and proteinuria. A diagnosis of SCD glomerulopathy was confirmed with renal biopsy. Treatment with angiotensin-converting enzyme inhibitor was initiated, and proteinuria rapidly reduced to 0.27 g/day. It is crucial for a clinician to recognize this important complication and take necessary precautions to delay progression to end-stage renal disease

Characteristics and outcomes of COVID-19 inpatients who underwent psychiatric consultations

Patients hospitalized with COVID-19 are at risk of developing many neuropsychiatric disorders, due to the effects of the disease on the brain and the psychosocial pressures of having the disease. The aim of the present study was to evaluate the characteristics and outcomes of patients who were hospitalized with a diagnosis of COVID-19, who underwent psychiatric consultations. The medical records of 892 patients hospitalized due to COVID-19 and the 89 among them who requested psychiatric consultations were analyzed retrospectively. After the psychiatric consultations, patients were most frequently diagnosed with delirium (38.2 %), adjustment disorder (27.0 %), depressive disorder (19.1 %) and anxiety disorder (11.2 %). Patients with delirium had longer hospital stays (p < 0.001), were transferred more frequently to intensive care units (p < 0.001), and had higher mortality rates during their hospital stays (p < 0.001), than all other patients. The need for oxygen (p < 0.001) and mechanical ventilation (p < 0.001) was also significantly higher in delirium patients, as well as in patients who received other psychiatric diagnoses. Neuropsychiatric disorders develop in patients receiving inpatient treatments in COVID-19 wards, and these disorders negatively affect the prognosis of COVID-19. Our findings suggest that the presence of neuropsychiatric disorders in in-patients with COVID-19 might be associated with the negative outcomes of the disease

A multicenter randomized trial for the effectiveness of structured discharge and follow-up protocol on readmission rate in COPD patients receiving LTOT/NIV: one-year interim analysis.

28th International Congress of the European-Respiratory-Society (ERS) -- SEP 15-19, 2018 -- Paris, FRANCEWOS: 000455567101063European Respiratory So

Approach of pulmonologists in Turkey to noninvasive mechanical ventilation use at home for chronic respiratory failure

WOS: 000386262800001PubMed ID: 27266279Introduction: To define approach of pulmonologists in Turkey to noninvasive mechanical ventilation ( NIV) use for chronic respiratory failure ( CRF), the most currently applied technique for home mechanical ventilation. Patients and Methods: A 38-question survey, developed and tested by the authors, was distributed throughout Turkey to 2205 pulmonologists by e-mail. Results: Twenty-seven percent of the pulmonologists responded ( n= 596). Domiciliary NIV was reported to be prescribed by 340 physicians [ 57.1% of all responders and 81% of pulmonologists practicing NIV at clinical practice ( n= 420)]. NIV prescription was associated with physician's title, type of hospital, duration of medical license, total number of patients treated with NIV during residency and current number of patients treated with NIV per week ( p< 0.05). Main estimated indications were listed as chronic obstructive pulmonary disease ( median, 25-75 percentile of the prescriptions: 75%, 60-85), obesity hypoventilation syndrome ( 10%, 2-15), overlap syndrome ( 10%, 0-20) and restrictive lung disease ( 5%, 2-10). For utilization of NIV at home, Bilevel positive airway pressure-spontaneous mode ( 40%, 0-80) and oronasal mask ( 90%, 60-100) were stated as the most frequently recommended mode and interface, respectively. Pressure settings were most often titrated based on arterial blood gas findings ( 79.2%). Humidifier was stated not to be prescribed by approximately half of the physicians recommending domicilliary NIV, and the main reason for this ( 59.2%) was being un-refundable by social security foundation. Conclusion: There is a wide variation in Turkey for prescription of NIV, which is supposed to improve clinical course of patients with CRF. Further studies are required to determine the possible causes of these differences, frequency of use and patient outcomes in this setting