Evaluation of a novel composite of expanded polystyrene with rGO and SEBS-g-MA.

This study displays the effect of reduced graphene oxide (rGO) nanofiller and polystyrene-b-poly(ethylene-ran-butylene)-b-polystyrene-grafted maleic anhydride (SEBS-g-MA) on the optical, thermal, and mechanical features of expanded polystyrene (EPS). First, the thin films of pristine EPS and composites were prepared using solution cast method. The prepared films were subjected to fourier-transform infrared (FTIR), SEM, UV-visible spectrophotometer, thermogravimetric analysis/differential scanning calorimetry, and universal testing machine for structural, morphological, optical, thermal, and mechanical characterizations. Optical study revealed a significant increase in refractive index and absorption of composites than EPS. Indirect band-gap energy of EPS (~4.08 eV) was reduced to ~1.61 eV for rGO composite and ~ 2.23 eV for composite composed of rGO and SEBS-g-MA. Thermal analyses presented improvement in characterization temperatures such as T10, T50, Tp, Tm, and Tg of composites, which ultimately lead to the thermal stability of prepared composites than pristine EPS. Stress-strain curves displayed higher yield strength (46.62 MPa), Young's modulus (96.29 MPa), and strain at break (0.54%) for EPS+rGO composite than pure EPS having stress at break (1.01 MPa), Young's modulus (12.44 MPa), and strain at break (0.08%). Moreover, ductility with relatively higher strain at break (0.61%) and lower Young's modulus (79.32 MPa) and yield strength (32.98 MPa) was noticed in EPS+rGO+SEBS-g-MA composite than EPS+rGO composite film. Morphological analysis revealed a change in globular morphology of EPS and inhomogeneous dispersion of rGO in EPS to homogeneously dispersed rGO in EPS matrix without globules owing to the addition of SEBS-g-MA. The increase in compatibility of EPS and rGO due to SEBS-g-MA was also observed in FTIR spectra. RESEARCH HIGHLIGHTS: Here, the solution casting approach was used to create the composite film of EPS and rGO with globules of various sizes. After adding SEBS-g-MA, the shape altered to globular free films exhibiting homogenous dispersion of rGO in EPS matrix. An optical investigation showed that composite materials had a significantly higher refractive index and absorption than EPS. The optical, thermal, and mechanical investigations suggest that the produced composites may be a great substitute for virgin EPS, allowing for a wider range of applications.

Nutrient Limitation Sensitizes Pseudomonas aeruginosa to Vancomycin.

Traditional antibacterial screens rely on growing bacteria in nutrient-replete conditions which are not representative of the natural environment or sites of infection. Instead, screening in more physiologically relevant conditions may reveal novel activity for existing antibiotics. Here, we screened a panel of antibiotics reported to lack activity against the opportunistic Gram-negative bacterium, Pseudomonas aeruginosa, under low-nutrient and low-iron conditions, and discovered that the glycopeptide vancomycin inhibited the growth of P. aeruginosa at low micromolar concentrations through its canonical mechanism of action, disruption of peptidoglycan crosslinking. Spontaneous vancomycin-resistant mutants underwent activating mutations in the sensor kinase of the two-component CpxSR system, which induced cross-resistance to almost all classes of ß-lactams, including the siderophore antibiotic cefiderocol. Other mutations that conferred vancomycin resistance mapped to WapR, an α-1,3-rhamnosyltransferase involved in lipopolysaccharide core biosynthesis. A WapR P164T mutant had a modified LPS profile compared to wild type that was accompanied by increased susceptibility to select bacteriophages. We conclude that screening in nutrient-limited conditions can reveal novel activity for existing antibiotics and lead to discovery of new and impactful resistance mechanisms.

Incidence, management, and outcome of molar pregnancies at a tertiary care hospital in quetta, pakistan.

Molar pregnancies represent a significant burden of disease on the spectrum of gestational trophoblastic diseases. The incidence appears to be higher in women from South Asia. The purpose of our prospective study was to determine the incidence, presentation, and outcomes of all molar pregnancies at our institution. During the study period, there were a total of 16,625 patients admitted to our department; out of whom 85 patients were diagnosed with a molar pregnancy. Vaginal bleeding was the commonest symptom (94.2%); theca lutein cysts were noted in 39% of the cases. Suction, dilatation, and curettage were noted to be the preferred method in almost all cases; hysterectomy was done in 12 (14.1%) patients. Single-agent chemotherapy was employed in high-risk patients and was well tolerated. Mean followup for these patients was 5.7 months (range 1-24 months). None of these patients developed persistent trophoblastic disease, invasive mole, or choriocarcinoma during the follow-up period.

Experience of emergency peripartum hysterectomies at a tertiary care hospital in quetta, pakistan.

Emergency peripartum hysterectomy (EPH) is associated with significant morbidity and mortality worldwide. The purpose of our paper was to determine the incidence, morbidity, and mortality of EPH done at our institution; the largest tertiary care government hospital in the city of Quetta, Pakistan. During the study period there were 12,642 deliveries, out of which 46 women had undergone an EPH, translating into an incidence of ∼4 per 1,000 births. Disturbingly, 82.6% of these patients had received no antenatal care prior to their presentation. There were 4 (8.7%) maternal deaths and 31 (67.4%) perinatal deaths. The commonest indication noted was uterine rupture in 21 (45.7%) cases. Lack of antenatal care is indeed a modifiable factor that needs to be addressed to help reduce maternal and fetal morbidity/mortality not only from emergency hysterectomies but also from all other preventable causes.

Quintuplets born to a woman without fertility treatment in Pakistan.

OBJECTIVE: To report a case of quintuplets born to a woman without fertility treatment along with a discussion on the incidence and management of related cases. DESIGN: Case report. SETTING: Bolan Medical College, Quetta, Pakistan. PATIENT(S): The quintuplets and their mother. INTERVENTION(S): Perinatal care. MAIN OUTCOME MEASURE(S): Perinatal morbidity and mortality in multiple gestation. RESULTS AND CONCLUSIONS: Quintuplets are a rare occurrence. This is even rarer if they are born to a woman without fertility treatment. The survival of the infants is even rarer. We here report a case of a woman who presented in her third trimester of gestation and gave birth to five babies through normal delivery; all of them are alive and doing well along with the mother of the babies. The learning points and issues for discussion in this case are fourfold. We present, first, an account of surviving quintuplets and their occurrence; second, the medical issues involved in the management and care of such cases; third, the psychologic and social consequences involved in these scenarios; and, finally, the plight and difficulties faced by a woman from a poor socioeconomic background along with the dilemma faced by a practicing clinician in a developing country.