Thermal and structural analysis of binary mixtures of pyrimidine liquid crystals using Modulated Differential Calorimetry and Synchrotron X-ray Diffraction measurements.

We present a systematic experimental dataset on the temperature dependence of specific heat capacity in a binary mixture of the second and seventh homologous series of 5-alkyloxy-2-(4-nonyloxy-phenyl) pyrimidine(PhP) liquid crystal compound. These binary mixtures exhibit nematic, smectic-A, and smectic-C phases within a concentration range of xPhP1 = 0 to 0.45. The liquid crystalline phases are structurally characterized using synchrotron X-ray diffraction. We determine the apparent molecular length in the nematic phase, smectic layer spacing, average distance between the long axes of molecules, correlation length, and orientational order parameters ( and ) as functions of temperature. The tilt angle in the SmC phase is inferred from the layer spacing data. To examine the critical behavior near the nematic to smectic A(NA) and smectic A to the smectic C (AC) phase transitions, we evaluate the critical exponents: α from specific heat capacity, ß from the fitting of the temperature-dependent tilt angle, and ν‖, ν⊥from the temperature-dependent longitudinal (ξ‖) and transverse (ξ⊥) correlation lengths. Modulated Differential Scanning Calorimetry (MDSC) measurements indicate the absence of phase shift, latent heat and imaginary specific heat capacity, suggesting that the AC transitions are second-order for all binary mixtures. The results obtained from heat capacity reveal that both the AC and NA transitions exhibit non-universal behaviours with effective exponents lying between the tricritical and 3D-XY values and follow nearly identical curve with decreasing width of the Sm-A and N phases. The Josephson hyperscaling relation is verified for both the NA and AC transitions in different mixtures. Moreover, knowing the heat capacity critical exponent α and the order parameter critical exponent ß, the susceptibility critical exponent γ for the AC transition can be estimated from Rushbrooke equality α+2ß+γ=2, with γ values ranging from 1.015 to 1.313, indicating the system's crossover character and apparently validating the Rushbrooke equality.

Static Permittivity and Electro-Optical Properties of Bi-Component Orthoconic Antiferroelectric Liquid Crystalline Mixtures Targeted for Polymer Stabilized Sensing Systems.

The behavior of two newly formulated bi-component orthoconic antiferroelectric liquid crystalline (OAFLC) systems, i.e., the Compound A + Compound B mixture system and Compound C + Compound B mixture system has been discussed in light of temperature and concentration dependencies of helical pitch length, spontaneous polarization, relaxation time, bulk viscosity, and the anchoring energy strength coefficient, together with static dielectric permittivity (ε) and dielectric anisotropy. Compound A + Compound B mixtures possess spontaneous polarization between 190-340 nC.cm-2 and fast relaxation times between 190-320 µs in the smectic antiferroelectric SmCA* phase at room temperature. Compound C + Compound B mixtures also have a spontaneous polarization in the range of 190-280 nC.cm-2 and relaxation times in the range of 190-230 µs at room temperature. Most of the mixtures have a helical pitch below one micrometer in the SmCA* phase. These advanced mixtures show a broad temperature range of the antiferroelectric SmCA* phase, fast switching of molecules under an applied electric field, negative dielectric anisotropy and a short helical pitch, confirming the advantage of designing new polymer-stabilized OAFLC that is targeted for novel application in sensing devices, utilizing the fast responsive electro-optical modulation elements.

Factors Influencing Antibiotic Prescribing Behavior and Understanding of Antimicrobial Resistance Among Veterinarians in Assam, India.

This study investigates factors influencing veterinarians' antibiotic prescribing behaviors and their understanding of antimicrobial resistance (AMR). The study used a telephone survey of 50 veterinarians conducted in five districts in Assam state, India. The survey sought information on the most prevalent animal diseases, veterinarians' awareness of potential preventive measures, including factors determining antimicrobial prescribing; the types of antimicrobials used for different health conditions in different species, and possible options to reduce antimicrobial use (AMU). The majority (86%) of respondents worked for the government, 98% reported having no written policy for the use of veterinary health products, and 58% have no on-site diagnostic facilities. Ceftriaxone, Enrofloxacin, and Oxytetracycline were the antibiotics (ABX) most frequently prescribed, by 76, 68, and 54% of veterinarians, respectively. These ABX were prescribed mainly for respiratory health problems and mastitis in cattle, and gastrointestinal infections in buffaloes, sheep, goat, and pigs. Severity of clinical symptoms, economic status of the livestock owner, and withdrawal period for ABX were ranked as very important factors for giving ABX. Less than two thirds (64%) were aware of the government ban for Colistin and only 2% were aware of a national plan for AMR. This study highlighted that ABX prescription is mostly based on tentative diagnosis given the lack of diagnostic facilities in most veterinary clinics. There is a need to enhance veterinary healthcare and to improve communication between policy makers and field veterinarians and, importantly, a need to disseminate clear prescribing guidelines on prudent AMU.

Adverse obstetrical and perinatal outcome in adolescent mothers associated with first birth: a hospital-based case-control study in a tertiary care hospital in North-East India.

PURPOSE: To analyze the adverse obstetrical and perinatal outcome of adolescent mothers associated with first birth. PATIENTS AND METHODS: This prospective case-control study was conducted in a tertiary care teaching hospital of North-East India between January 2014 and December 2014. All adolescent primigravidae completing 28 weeks of gestation with singleton pregnancy and delivered at our institution were included in the study group. Primigravidae aged between 20 and 25 years were taken as a control group. Mothers having pregnancy complicated with diabetes mellitus, renal disorder, thyroid disorders, and cardiac diseases were excluded from the study. Demographic data, maternal complications like severe anemia, pre-eclampsia, eclampsia, gestational age at delivery, mode of delivery, and postpartum complications were compared. Among fetal complications, low-birth weight, preterm birth, neonatal intensive care unit admission, still birth, and early neonatal death were compared. All the patients were interviewed regarding contraceptive knowledge and its use preceding the pregnancy. RESULTS: Quality antenatal care was received by 80.6% of adolescent mothers. The adolescent mothers had a higher incidence of pre-eclampsia (odds ratio [OR] 2.017 95% confidence interval [CI]: 1.045-3.894, P=0.03), preterm deliveries (OR: 1.655, 95% CI: 1.039-2.636, P=0.03). Among fetal outcomes, the low- birth weight babies (OR: 1.59, 95% CI: 1.016-2.478), low mean birth weight (2,544.4±622.09 g versus 2,701.6±582.51 g), and higher admission to neonatal intensive care unit (OR: 1.957, 95% CI: 1.120-3.417) were significantly associated with adolescent mothers. There was no significant difference found regarding the mode of delivery, still birth, and early neonatal death. Moreover, contraceptive knowledge and its use were found to be poor among adolescent mothers. CONCLUSION: With quality antenatal, intranatal, and postnatal care, the obstetric risk of childbirth in adolescent mothers may not be as serious as perceived to be.

Necrotizing fasciitis - a rare complication following common obstetric operative procedures: report of two cases.

Necrotizing fasciitis, a near-fatal soft-tissue infection complicating obstetric operative wounds, is a rare entity in obstetrics. Herein, we report two cases of necrotizing fasciitis in severely undernourished and anemic women following obstetric operative procedures. Both undernourishment and anemia compounded the already existing immune-suppressed state in pregnancy and may have lead to life-threatening necrotizing fasciitis. One of the patients developed necrotizing fasciitis following episiotomy and the other following cesarean section. Both the cases were diagnosed clinically. Management was done by total parenteral nutrition, prompt correction of anemia, and surgical debridement under broad-spectrum antibiotic coverage. The raw areas were later reconstructed by split skin grafting in the first case, whereas, in the second case, due to the patient's refusal of skin grafting, the wound was allowed to heal by secondary intention. Both patients survived, although with morbidity. Our study aims to emphasize prompt correction of comorbidities along with aggressive management of necrotizing fasciitis for better outcomes in the obstetric population. Prompt correction of nutritional status improves the survival rate.

Antifertility efficacy of Drynaria quercifolia (L.) J. Smith on female Wister albino rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Plant based traditional medicines for birth control has been in practice in rural populations of North-East India, since time immemorial. Fresh rhizome of Drynaria quercifolia (L.) J. Smith is one of the plant parts used traditionally by different ethnic communities in Tripura, India for birth control. The present investigation is aimed to justify the scientific basis in traditional use of Drynaria quercifolia rhizome as anti-fertility agent. MATERIALS AND METHODS: Ex-vivo uterotonic activity was done on uterine tissue. Acute toxicity test of the plant extract was carried out in rats of both sexes. The abortifacient and anti-implantation activities of the extract were investigated, in-vivo and estimated the level of different hormones release. RESULTS: The result revealed the effectiveness of methanol (87%) and aqueous (68%) extract of the plant on uterotonic activity. The extracts showed relatively non-toxic effect in acute toxicity study. Methanolic extract has shown higher efficacy for both abortifacient (**p<0.01) and anti-implantation performance (**p<0.01) and also effected hormone release level (**p<0.01). CONCLUSION: Methanolic extract of Drynaria quercifolia (L.) J. Smith rhizome has been proved to have significant anti-fertility activity.

Determination of the orientational order parameter of the homologous series of 4-cyanophenyl 4-alkylbenzoate (n.CN) by different methods.

The orientational order parameters of a homologous series of 4-cyanophenyl 4-alkylbenzoates have been determined at different temperatures from (13)C-NMR, x-ray diffraction, optical birefringence, high resolution density and diamagnetic susceptibility anisotropy measurements. To determine the temperature dependence of the orientational order parameter from the (13)C chemical shift values, the two-dimensional polarization inversion spin exchange at the magic angle (PISEMA) method was also used for the measurement of (13)C-(1)H dipolar couplings at different sites in the oriented phase. The nematic order parameters determined from each of these methods have been compared. Apart from a slight shift in their values their trends with temperature are very similar. The differences among the results obtained by these five different methods have been discussed. From the high resolution density data, the values of the critical exponents near the T(N-I) transition are found to lie between the Ising model and tricritical behaviour.

Determination of the orientational order parameter of a binary mixture showing an induced smectic A(d) phase from magnetic susceptibility measurements.

The diamagnetic susceptibility anisotropy (Δχ) measurement of a binary mixture comprising of a strongly polar mesogen (CPPCC) and a weakly polar mesogen (ME6O.5) showing an induced smectic A(d) phase is reported here. Assuming an axially symmetric molecule, the temperature dependence of the orientational order parameter ⟨P(2)⟩ has been investigated from the anisotropy of the susceptibility at different temperatures throughout the entire composition range. The results are compared with x-ray and optical birefringence measurements along with the mean-field theory of the smectic A phase. The maximum in the stability of the smectic A(d) phase (at x(CPPCC) = 0.33) corresponds to the minimum in the order parameter values. The order of the smectic to nematic phase transition has also been discussed.