Comparative cryopreservation of indian wild orange (Citrus indica Tanaka) embryonic axes

BACKGROUND

Indian Wild Orange (Citrus indica Tanaka) is an endangered and endemic species from northeast India for which effective ex situ conservation strategies, including embryo cryopreservation, are urgently needed.

MATERIALS AND METHODS

Desiccation tolerance and cryopreservation ability for embryonic axes of Citrus indica was determined using three techniques (air desiccation-freezing, PVS2 vitrification-freezing and encapsulation-dehydration-freezing). Success was assessed as survival and recovery in vitro.

RESULTS

Successful cryopreservation of embryonic axes was achieved using all three methods, with the highest survival achieved when using air desiccation-freezing (90%) followed by encapsulation-dehydration (85%) and PVS2 vitrification cryopreservation (80%). Regeneration levels were lower than survival levels for all three proceedures. Post-cryo regeneration success was: encapsulation-dehydration (64%) > air desiccation-freezing (55%) > PVS2 vitrification (52%).

CONCLUSION

Although there was relatively high post-cryopreservation recovery growth obtained using all the three techniques, the air desiccation-freezing technique is preferred, as it is a simple, practical and reproducible technique for the long-term cryobanking of this important wild species. Doi: 10.54680/fr23310110512.

Multiwavelength Speciation in Pyrolysis of n-Pentane and Experimental Determination of the Rate Coefficient of nC5H12 = nC3H7 + C2H5 in a Shock Tube

We report the application of a multiwavelength speciation strategy to the study of n-pentane (nC₅H₁₂) pyrolysis behind reflected shock waves in a shock tube. Experiments were conducted with 2% nC₅H₁₂/0.8%CO₂/Ar (by mole) between 1150 and 1520 K in the pressure range of 1-2 atm. Utilization of laser absorption spectroscopy at eight wavelengths allowed time-resolved measurements of n-pentane, ethylene, methane, heavy alkenes, and temperature. The measured time histories were compared against the predictions of four recently developed chemical kinetic models for heavy hydrocarbons. It was found that none of the models reconciled the measured species time histories simultaneously. Sensitivity analysis was conducted to identify key reactions influencing the evolution of ethylene and other major pyrolysis products. The analysis revealed that the unimolecular decomposition of n-pentane into n-propyl and ethyl radicals has a dominating influence over the evolution of ethylene in the temperature range of 1150-1450 K. The rate coefficient of this reaction was then adjusted to match the measured ethylene time histories for each experiment. The rate coefficients thus determined, were fit against temperature using an Arrhenius expression given by k₁(T) = 3.5 × 10¹⁴ exp(-67.2 kcal/RT) s^-1. The average overall 2σ uncertainty of the measured rate coefficient was found to be ±35%, resulting primarily from uncertainties in the rate coefficients of secondary reactions. The measured rate coefficient, when used with the models, leads to a significant improvement in the prediction of species time histories. Further improvements in the model are possible if the rate coefficients of relevant reactions pertaining to small hydrocarbon chemistry are determined with an improved accuracy, and less uncertainty. To the best knowledge of the authors, this is the first experimental determination of the rate coefficient of C₅H₁₂ → nC₃H₇ + C₂H_5.

The Effect of Photodynamic Therapy on Oral-Premalignant Lesions: A Systematic Review

Background

Material and Methods

Results

Conclusions

Impact of simplifications on numerical modelling of the shallow subsurface at city-scale and implications for shallow geothermal potential

Anthropogenic infrastructures in the shallow subsurface, such as heated basements, tunnels or shallow geothermal systems, are known to increase ground temperatures, particularly in urban areas. Numerical modelling helps inform on the extent of thermal influence of such structures, and its potential uses. Realistic modelling of the subsurface is often computationally costly and requires large amounts of data which is often not readily available, necessitating the use of modelling simplifications. This work presents a case-study on the city centre of Cardiff, UK, for which high resolution data is available, and compares modelling results when three key modelling components (namely ground elevation, hydraulic gradient distribution and basement geometry) are implemented either 'realistically', i.e. with high resolution data, or 'simplified', utilising commonly accepted modelling assumptions. Results are presented at a point (local) scale and at a domain (aggregate) scale to investigate the impacts such simplifications have on model outputs for different purposes. Comparison to measured data at individual locations shows that the accuracy of temperature outputs from numerical models is largely insensitive to simplification of the hydraulic gradient distribution implemented, while changes in basement geometry affect accuracy of the mean temperature predicted at a point by as much as 3.5 °C. At the domain scale, ground temperatures within the first 20 m show a notable increase (approximately 1 °C volume-averaged and 0.5 °C surface-averaged), while the average heat flux over the domain is about 0.06 W/m² at 20 m depth. These increased temperatures result in beneficial conditions for shallow geothermal utilisation, producing drilling cost savings of around £1700 per typical household system or about 9% increase in thermal energy potential. Simplifications of basement geometry and (to a lesser degree) the hydraulics can result in an overestimation of these temperatures and therefore over-predict geothermal potential, while the elevation simplification showed little impact.

Storage Behavior and Cryopreservation of Citrus cavaleriei, an Endangered, Cold-resistant Species of Northeast India with Exceptionally Large Seeds

BACKGROUND

Ichang Papeda (Citrus cavaleriei H.Lév. ex Cavalerie) is a wild and endangered species of NE India that requires urgent preservation of its genetic resources.

OBJECTIVE

To characterize the storage physiology of the seeds and to cryopreserve the embryo and embryonic axis (EA).

MATERIALS AND METHODS

The morphology and storage physiology of the seeds were determined, and the cryopreservation of embryos and EA attempted using various techniques (viz., air desiccation-freezing, vitrification and encapsulation-dehydration).

RESULTS

Weighing up to 4 g, seeds of Citrus cavaleriei are the largest known in the genus. Based on estimates using the seed coat ratio - seed mass (SCR-SM) model there was a very high probability of seed desiccation intolerance, which was validated physiologically; seeds lost vigour on drying below 30% moisture content (MC) and no seeds germinating after drying to <12% MC. Embryos and EAs could be air dried to 25-30% MC and cryopreserved with c. 50% survival. In contrast, EA optimally exposed to PVS2 (20 min) or encapsulated, sucrose pretreated (0.5 M, 24 h) and dehydrated (6 h) had c. 40% survival after cryopreservation.

CONCLUSION

Citrus cavaleriei produces large, recalcitrant seeds that can, nevertheless, be cryopreserved as embryos or isolated EA after air drying to c. 25-30% MC; encapsulation-dehydration and vitrification provide alternative options for the cryopreservation of EA.

Potential use of hydroxychloroquine, ivermectin and azithromycin drugs in fighting COVID-19: trends, scope and relevance

Alarming situation has been caused due to the emergence of COVID-19 infection around the world. There is an urgency of developing a therapeutic strategy in order to control the spread of COVID-19. Towards that initiative, potential drugs like hydroxychloroquine, ivermectin and azithromycin have been tested by diverse group of researchers worldwide for their potential against novel coronavirus. The present report presents together the comprehensive knowledge derived from the major researches about the above drugs altogether in context of the current health emergency around the world. Hydroxychloroquine and ivermectin were known to act by creating the acidic environment and inhibiting the importin (IMPα/β1) mediated viral import. Azithromycin was found to act similar to the hydroxychloroquine as an acidotropic lipophilic weak base. All the three categories of drugs seemed to potentially act against novel coronavirus infection. However, their efficacies need to be studied in detail individually and in combination in-vivo in order to combat COVID-19 infection.

Shock Tube Measurement of the CH3 + C2H6 → CH4 + C2H5 Rate Constant

The rate constant for the CH₃ + C₂H₆ → CH₄ + C₂H₅ reaction was studied behind reflected shock waves at temperatures between 1369 and 1626 K and pressures from 8.6 to 47.4 atm in mixtures of methane, ethane, and argon. Ethylene time histories were measured using laser absorption of radiation from a carbon dioxide gas laser near 10.532 μm. The resulting rate constant data can be represented by the Arrhenius equation k (T) = 3.90 × 10¹³ exp(-16670 cal/mol/RT) cm³ mol^-1 s^-1. We believe this is the first study to extend experimental data for this rate constant to temperatures above 1400 K. The overall 2σ uncertainty of the current data is +18%/-21% resulting primarily from uncertainties associated with the influence of secondary reactions and the fitting of rapidly changing species time histories at the higher temperatures.

Shock Tube Measurement of the C2H4 + H ⇔ C2H3 + H2 Rate Constant

The rate constant for the reaction C₂H₄ + H ⇔ C₂H₃ + H₂ was studied behind reflected shock waves at temperatures between 1619 and 1948 K and pressures near 10 atm in a mixture of C₂H₄, CH₄, H₂, and argon. C₂H₄ time histories were measured using laser absorption of a CO₂ gas laser near 10.53 μm. Experimental mixtures were designed to optimize sensitivity to the title reaction with only weak sensitivity to secondary reactions. Two mechanisms, FFCM1 and ARAMCO v2, are used for data analysis. The well-selected operating conditions and Monte Carlo sampling data analysis procedure resulted in mechanism-independent reaction rate constant measurements with a 2σ uncertainty of ±35%. The current data disagree with a broadly used theoretical calculation (Knyazev et al. (1996)), but they are in good consensus with one of the review studies (Baulch et al. (2005)), k = (3.9 × 10²²) T^3.62 exp(-5670/ T) cm³ molecule^-1 s^-1. To the best of our knowledge, this work provides the first high-temperature study of the C₂H₄ + H ⇔ C₂H₃ + H₂ reaction rate constant with well-defined uncertainty.

An interesting case of primary hypoparathyroidism

Primary hypoparathyroidism can occur due to an activating mutation of calcium sensing receptor (CaSR). Most patients remain asymptomatic and therefore not diagnosed until adulthood. We present a 38-year-old lady who had a history of muscle cramps since 8 years. She presented with vomiting, abdomen pain and body ache, showed clinical evidence of hypovolemia, severe hypocalcemia, hypokalemia, hypomagnesemia, hyperphosphatemia and metabolic alkalosis. Her 24 h urinary phosphorus was low and 24 h urinary excretion of sodium, potassium and chloride were high. Her intact parathormone was on the lower side of the normal range. She improved once we had corrected her biochemical abnormalities. By excluding acquired causes of hypoparathyroidism, we are able to conclude that this may be a case of primary hypoparathyroidism due to activating mutation of CaSR.

Chlamydia pneumoniae seropositivity in adults with acute ischemic stroke: A case-control study

BACKGROUND

Causative role of Chlamydia pneumoniae infection in patients with acute ischemic stroke (AIS) remains unresolved till date.

AIM

To investigate the role of C. pneumoniae antibodies in AIS.

MATERIALS AND METHODS

Patients with AIS and sex- and environment-matched controls were enrolled. Antibodies to C. pneumoniae (IgA, IgG and IgM) were measured using enzyme-linked immunosorbent assay (ELISA).

RESULTS

A total of 51 patients and 48 controls were enrolled. The IgA seropositivity was significantly associated with AIS (unadjusted odds ratio 3.1; 95% CI 1.38, 6.96; P = 0.005), whereas IgG (unadjusted OR 0.44; 95% CI 0.18, 1.09; P = 0.07) and IgM (unadjusted OR 1.1; 95% CI 0.36, 3.3; P = 0.88) were not. There was no difference in IgA or IgG positivity in different stroke subtypes. On multivariate analysis after adjusting for sex, hypertension, diabetes mellitus, smoking and alcohol, the IgA seropositivity yielded an adjusted OR for stroke (4.72; 95% CI 1.61, 13.83; P = 0.005), while IgG seropositivity did not (OR 0.25; 95% CI 0.08, 0.83; P = 0.23).

CONCLUSIONS

An increased risk of AIS was demonstrated in patients seropositive for C. pneumoniae for IgA antibodies.

Are we good at thromboembolic disease prophylaxis - an audit of the use of risk assessment forms in emergency medical admissions

Venous thromboembolism (VTE) is a major cause of morbidity and mortality in hospitalised patients. Thromboprophylaxis is an effective strategy for VTE prevention in high-risk patients. An initial audit in our district general hospital trust showed poor adherence to the thromboembolic risk factors consensus group recommendations and so a risk assessment form (RAF) was devised. We present repeated audits to assess the RAF uptake and its effects on VTE thromboprophylaxis. We also present data analysing perceptions among doctors of the RAF and reasons for its poor completion. We provide compelling evidence that the RAF is an invaluable tool in the assessment of VTE thromboprophylaxis.

Building for the future: influence of housing on intelligence quotients of children in an urban slum

INTRODUCTION

Interventions on behalf of the marginalized in society can assume many formats. In an urban slum the Government of Delhi built one-room houses for some of the residents in what is termed a 'plot area'. Not all residents could be accommodated in the project and the remainder continued to live next door in shanty houses of the slum. Nineteen years later, young children who had migrated with their parents, have grown up and have children of their own. We looked at the development of the children living in the two types of accommodation.

METHODS

A total of 373 children were studied. All children (n = 200) between the ages of 3.5 and 5.5 years in a cluster of five residential blocks in the plot area were studied. As a control, children in two large clusters of shanty houses (n = 173) were also studied. For development assessment the Central Institute of Education (CIE) Test was performed. This is an Indian adaptation of the Standford-Binet Test. Multiple regression analysis was utilized to determine the factors that influenced IQ most.

RESULTS

The mean IQ of the children in the plot area was 92.5 (s.d. 13.38) and in the shanty houses 89.5 (s.d. 12.9) (p = 0.05). Analysis showed that the most significant factors affecting IQ were malnutrition in the first 6 months of life and attendance of the child at pre-school. For nutrition in the first 6 months, there was no difference between the groups. For attendance at pre-school, 110 of 200 in the plot area and 47 of 173 in the shanty houses were attending pre-school (p < 0.01).

CONCLUSION

We find that children living in the permanent houses had a significantly better IQ than those in shanty houses. A review of the literature did not reveal a comparable study.

Hospital epidemiology of dry eye

One hundred consecutive cases of dry eye were studied to comment upon its epidemiological aspects. The incidence of dry eye amongst ophthalmic outpatients was 0.46% with a male:female ratio of 1:1.22. Fifty seven percent of the patients were above 50 years of age. The incidence was higher amongst outdoor workers and people from rural areas with poor socioeconomic status. The influence of hot and dry climate and nutritional status on dry eye incidence is discussed.

The long-term prognosis of patients with out-of-hospital cardiac arrest but no inducible ventricular tachycardia

The long-term prognosis of patients successfully resuscitated from cardiac arrest who do not have acute precipitating factors and in whom ventricular arrhythmias cannot be induced during baseline electrophysiologic testing is controversial. The purpose of this investigation was to evaluate the long-term risk of recurrent sudden death and determine the clinical, angiographic, hemodynamic, and electrophysiologic predictors of recurrent cardiac arrest in such patients. Twenty-six (37%) of 71 consecutive patients with a single episode of aborted sudden death did not have inducible ventricular arrhythmias (less than 7 intraventricular responses) during baseline drug-free electrophysiologic study and they form the basis of this report. Their mean age was 54 +/- 13 (mean +/- SD) years and the left ventricular ejection fraction (LVEF) was 0.47 +/- 0.17. After a mean follow-up period of 16 months, 11 patients (42%) had a recurrent cardiac arrest (fatal in 10 patients). The actuarial incidence of recurrent cardiac arrest was 30 +/- 10% at 1 year and 55 +/- 13% at 3 years. Patients with LVEF less than or equal to 0.40 had a significantly higher occurrence of recurrent cardiac arrest than those with LVEF greater than 0.40 (p = 0.02; 1-year actuarial incidence of 57 +/- 17% versus 13 +/- 19%). Patients with recurrent sudden death had a significantly greater incidence of dilated cardiomyopathy (55% versus 7%; p = 0.02) and baseline frequent premature ventricular contractions (PVCs greater than 10/hr; 64% versus 17%, p = 0.036) or nonsustained ventricular tachycardia (36% versus 0%; p = 0.37) than patients without these characteristics.(ABSTRACT TRUNCATED AT 250 WORDS)