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1.
Int J Trichology ; 15(2): 63-69, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37701557

RESUMO

Context: Alopecia areata (AA) is the most common cause of inflammatory, nonscarring hair loss, involving hair-bearing areas of the body. The etiology of AA still remains uncertain; however, genetic, environmental, and autoimmunity play a role. Newer theories such as oxidative theory, HPA axis activation, and finally, the role of increased inflammatory cytokines such as interleukin 1 (IL1), tumor necrosis factor-alpha, interferon-gamma, IL-2 IL-4, and MIF are suggested to contribute to both AA and metabolic syndrome (MS). Aims: Assessment of the degree of association of MS (NCEP ATP III criteria) in clinically diagnosed cases of AA and compare to that of controls. Materials and Methods: Similar age/sex-matched AA patients and controls (106 in each group) were taken. Anthropometric measurements, blood-sugar estimation, lipid-profile estimation in venous blood sample, and blood-pressure measurement were done. Results: Prevalence of MS was almost similar among cases of AA 9/106 (8.47%) as well as healthy controls 8/106 (7.54%), and the difference was not statistically significant (P = 1). Among all components of MS, waist circumference (WC) (central obesity) was the most common parameter (100% cases). In controls, high systolic blood pressure (SBP) was the most common parameter (77.78% controls). AA is associated with a higher level of SBP, diastolic blood pressure (DBP), WC although nonsignificant, and low level of high-density lipoprotein cholesterol which was the only significant association. Conclusion: Insignificant correlation between occurrence of MS and evidence of insulin resistance (IR) in AA was observed in this study population. However, some of the observations in the present study may raise awareness in susceptible individuals that lifestyle changes and regular screening in AA can reduce the risk of cardiovascular diseases and other co-existing autoimmune inflammatory condition-IR, dyslipidemia, and hypertension.

2.
BJOG ; 130(9): 1007-1015, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-36852501

RESUMO

OBJECTIVE: To evaluate the effectiveness of tranexamic acid (TXA) in reducing blood loss during elective caesarean sections in women with and without risk factors for postpartum haemorrhage (PPH). DESIGN: A double-blind, randomised placebo-controlled trial. SETTING: An academic tertiary referral centre in Singapore. POPULATION: Multiethnic women aged 21 years or older undergoing elective caesarean section. METHODS: Randomisation to intravenous TXA or normal saline (placebo) 10 minutes before skin incision. MAIN OUTCOME MEASURES: Calculated estimated blood loss (cEBL), derived from blood volume and haematocrit levels. RESULTS: Between June 2020 and October 2021, 200 women were randomised to the placebo or TXA groups. Women who received prophylactic TXA had a significantly lower mean cEBL compared with those receiving placebo (adjusted mean difference -126.4 mL, 95% CI -243.7 to -9.1, p = 0.035). The effect was greatest in those at high risk for PPH, with a reduction in cEBL (mean difference -279.6 mL, 95% CI -454.8 to -104.3, p = 0.002) and a lower risk of cEBL ≥500 mL (risk ratio [RR] 0.54, 95% CI 0.36-0.83, p = 0.007) and cEBL ≥1000 mL (RR 0.44, 95% CI 0.20-0.98, p = 0.016). Subgroup analysis showed benefit for women with preoperative haemoglobin <10.5 g/dL (mean difference -281.9 mL, 95% CI -515.0 to -48.8, p = 0.019). There was no significant difference in need for additional medical or surgical interventions. There were no maternal or neonatal adverse outcomes. CONCLUSION: Prophylactic TXA should be considered in women with risk factors for PPH, and those most likely to benefit are those with preoperative haemoglobin <10.5 g/dL.


Assuntos
Hemorragia Pós-Parto , Ácido Tranexâmico , Recém-Nascido , Feminino , Gravidez , Humanos , Ocitocina/uso terapêutico , Hemorragia Pós-Parto/prevenção & controle , Hemorragia Pós-Parto/tratamento farmacológico , Ácido Tranexâmico/uso terapêutico , Cesárea/efeitos adversos , Método Duplo-Cego , Hemoglobinas
4.
Indian J Sex Transm Dis AIDS ; 42(1): 7-13, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34765931

RESUMO

CONTEXT: Inguinal skin is prone to various infectious dermatological conditions such as erythrasma, intertrigo, hidradenitis suppurativa, folliculitis, dermatophytic infection, and various sexually transmitted diseases, as compared to the skin elsewhere. AIM: Our study attempts to compare the biophysical profile parameters (BPPs) of the genital skin with that of the rest of the body, while taking skin of the upper back as control. It also attempts to find out if there is a difference in BPPs of the two sites and that how the change in the BPPs, bring about change in microbiome and make inguinal skin more prone to infections. MATERIALS AND METHODS: This was a hospital-based comparative study conducted over 976 patients (600 males and 376 females) of age group 18-60 years, where BPP parameters such as hydration, skin pH, transepidermal water loss (TEWL), and sebum content were measured over the skin of the upper back and right inguinal region, and the results were summarized and presented as proportions (%). Chi-square test was used to compare abnormal findings. P ≤ 0.05 was taken as statistically significant. MedCalc 16.4 version software was used for all statistical calculations. RESULTS: Significant difference was noted in skin pH and TEWL, where P value came out to be <0.05, which was statistically significant, whereas there was minimal difference in sebum content and skin hydration in both the areas, in males and females. CONCLUSION: Raised skin pH disturbs organization of lipid bilayers (disturbed barrier), decreases lipid processing (impaired SC cohesion), and increases serine protease activity (reduced AMP). Increased TEWL (defect in physical barrier) and decreased hydration predispose the genital skin to infections. Use of pH buffered solutions (3-4), barrier repair creams containing ceramides, and barrier protective creams with dimethicone can help prevent these inguinal dermatoses.

5.
Nat Commun ; 12(1): 3839, 2021 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-34158493

RESUMO

Regarded as the most important ion in interstellar chemistry, the trihydrogen cation, [Formula: see text], plays a vital role in the formation of water and many complex organic molecules believed to be responsible for life in our universe. Apart from traditional plasma discharges, recent laboratory studies have focused on forming the trihydrogen cation from large organic molecules during their interactions with intense radiation and charged particles. In contrast, we present results on forming [Formula: see text] from bimolecular reactions that involve only an inorganic molecule, namely water, without the presence of any organic molecules to facilitate its formation. This generation of [Formula: see text] is enabled by "engineering" a suitable reaction environment comprising water-covered silica nanoparticles exposed to intense, femtosecond laser pulses. Similar, naturally-occurring, environments might exist in astrophysical settings where hydrated nanometer-sized dust particles are impacted by cosmic rays of charged particles or solar wind ions. Our results are a clear manifestation of how aerosolized nanoparticles in intense femtosecond laser fields can serve as a catalysts that enable exotic molecular entities to be produced via non-traditional routes.

6.
Dermatology ; 237(5): 797-805, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33445175

RESUMO

BACKGROUND: Whether HAIR-AN syndrome and polycystic ovarian syndrome (PCOS) are distinct entities or represent a phenotypic spectrum of the same syndrome is still unclear. HAIR-AN syndrome is characterized by high insulin resistance, obesity, and hyperinsulinemia as compared to PCOS and could represent adipose tissue dysfunction as the primary pathophysiologic trigger. This study was undertaken to study the role of adipose tissue dysfunction in HAIR-AN syndrome and PCOS using adipocytokines as surrogate markers of "adiposopathy." MATERIALS AND METHODS: A cross-sectional observational study was conducted at a tertiary care hospital over a period of 1 year. Serum adiponectin, leptin, IL-6, and TNF-α levels were measured in 30 women with HAIR-AN syndrome and in 30 women with PCOS. Correlations between adipocytokines, inflammatory markers, serum testosterone, and serum insulin were determined. Data analysis was performed using the SPSS version 23.0 (IBM SPSS Statistics Inc., Chicago, IL, USA) software program. RESULTS: Women with HAIR-AN syndrome had significantly higher hyperandrogenemia, hyperinsulinemia, and insulin resistance as compared to PCOS women. They also had high leptin levels and lower adiponectin levels (p < 0.001). However, the levels of inflammatory markers (TNF-α and IL-6) were similar in both the groups (p > 0.05). Serum adiponectin showed a negative correlation with HOMA-IR and testosterone levels, while leptin showed a positive correlation with both in HAIR-AN patients while no such correlation was found in the PCOS group. CONCLUSION: The significantly raised adipocytokines in HAIR-AN syndrome patients as compared to PCOS patients indicates the primary role of adipose tissue dysfunction ("adiposopathy") in the pathogenesis of HAIR-AN syndrome while only a minor role, if any, in PCOS. Both these syndromes stand as distinct entities pathogenically with an overlapping phenotype.


Assuntos
Acantose Nigricans/sangue , Acantose Nigricans/complicações , Tecido Adiposo/fisiopatologia , Hiperandrogenismo/sangue , Hiperandrogenismo/complicações , Síndrome do Ovário Policístico/sangue , Síndrome do Ovário Policístico/complicações , Adiponectina/sangue , Tecido Adiposo/metabolismo , Tecido Adiposo/patologia , Adolescente , Adulto , Povo Asiático , Estudos Transversais , Feminino , Humanos , Índia , Resistência à Insulina , Interleucina-6/sangue , Leptina/sangue , Fator de Necrose Tumoral alfa/sangue , Adulto Jovem
7.
J Phys Chem Lett ; 11(22): 9842-9845, 2020 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-33207882

RESUMO

Zhang and co-workers ( J. Phys. Chem. Lett. 2020, 11, 1100-1105) have recently reported results of experiments involving irradiation of argon clusters doped with bromofluorene chromophores by nanosecond-long pulses of 532 nm laser light. Multiply charged ions of atomic argon (Arn+, 1 ≤ n ≤ 7) and carbon (Cn+, 1 ≤ n ≤ 4) are observed, which are sought to be rationalized using an evaporation model. The distinguishing facet of exploding clusters being progenitors of energetic ions and electrons constitutes the key driver for contemporary research in laser-cluster interactions; it is, therefore, important to point out inconsistencies that are intrinsic to the model of Zhang and co-workers. In light of similar reports already in the literature, we show that their model is of limited utility in describing the dynamics that govern how fast, multiply charged atomic ions result from laser irradiation of gas-phase clusters. We posit that it is plasma behavior that underpins cluster heating and cluster explosion dynamics.

8.
J Phys Chem A ; 124(8): 1508-1514, 2020 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-32040313

RESUMO

Electrons and •OH-radicals have been generated by using low-energy laser pulses of 6 ns duration (1064 nm wavelength) to create plasma in a suspension of plasmid DNA (pUC19) in water. Upon thermalization, these particles induce single and double strand breakages in DNA along with possible base oxidation/base degradation. The time-evolution of the ensuing structural modifications has been measured; damage to DNA is seen to occur within 30 s of laser irradiation. The time-evolution is also measured upon addition of physiologically relevant concentrations of salts containing monovalent, divalent, or trivalent alkali ions. It is shown that some alkali ions can significantly inhibit strand breakages while some do not. The inhibition is due to electrostatic shielding of DNA, but significantly, the extent of such shielding is seen to depend on how each alkali ion binds to DNA. Results of experiments on strand breakages induced by thermalized particles produced upon plasma-induced photolysis of water, and their inhibition, suggest implications beyond studies of DNA; they open new vistas for utilizing simple nanosecond lasers to explore the effect of ultralow energy radiation on living matter under physiologically relevant conditions.


Assuntos
Quebras de DNA de Cadeia Dupla , DNA/química , Elétrons , Radical Hidroxila/química , Plasmídeos , Termodinâmica , Água/química
9.
J Clin Aesthet Dermatol ; 12(5): 34-38, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31320975

RESUMO

Introduction: Acne vulgaris is a chronic inflammatory disorder of the pilosebaceous units and has been associated with hyperandrogenism, which, in women, is most commonly caused by polycystic ovary syndrome (PCOS). Metformin treatment can correct ovarian and functional adrenal hyperandrogenism in adolescents with PCOS. Objective: We evaluated the efficacy of metformin therapy in women with acne and PCOS in terms of acne load. Methods: This was a hospital-based, interventional, longitudinal study that included 40 female patients with acne and PCOS diagnosed using the Rotterdam criteria. Hormonal assay, including serum levels of testosterone, dehydroepiandrosterone sulphate, luteinizing hormone, follicle-stimulating hormone, prolactin, and blood sugar, was conducted on the third or fourth day of the menstrual cycle in a fasted state. An abdominal ultrasound was performed on the ninth day of menstrual cycle to diagnose PCOS. Baseline acne severity was assessed as per the Definition Severity Index. Metformin 500mg was given to all selected patients three times a day for eight weeks. Patient follow-up and acne severity reassessment was conducted at Weeks 3 and 6. At Week 8, all work-ups were repeated. Intention-to-treat analysis was done. Wilcoxin signed-rank sum test was used to identify significance in acne severity. Results: Metformin treatment significantly reduced acne severity in patients with PCOS (p<0.001). Conclusion: Metformin reduces ovarian hyperandrogenism, leading to clinical improvement of acne in women with PCOS.

10.
J Phys Chem A ; 123(15): 3241-3247, 2019 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-30920832

RESUMO

Low-power laser pulses of 6 ns duration (1064 nm wavelength) have been used to create plasma in an aqueous solution of plasmid DNA (pUC19). Thermal energy electrons and •OH radicals in the plasma induce strand breakages in DNA, including double strand breaks and possible base oxidation/base degradation. The time evolution of these modifications shows that it takes barely 30 s for damage to DNA to occur. Addition of physiologically relevant concentrations of a salt (NaCl) significantly inhibits such damage. We rationalize such inhibition using simple electrostatic considerations. The observation that DNA damage is induced by plasma-induced photolysis of water suggests implications beyond studies of DNA and opens new vistas for using simple nanosecond lasers to probe how ultralow energy radiation may affect living matter under physiological conditions.


Assuntos
Quebras de DNA de Cadeia Dupla/efeitos dos fármacos , DNA/química , Nanoestruturas/química , Sódio/química , DNA/efeitos da radiação , Quebras de DNA de Cadeia Dupla/efeitos da radiação , Elétrons , Radical Hidroxila , Lasers , Luz , Oxirredução , Fotólise , Cloreto de Sódio/química , Eletricidade Estática , Água/química
11.
Langmuir ; 35(31): 10139-10150, 2019 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-30441906

RESUMO

Recent work is summarized that shows how microbubbles may have potential utility in biomedical situations as (i) highly localized generators of intense white light in an aqueous environment, (ii) disruptors of matter in aqueous solution, (iii) essential precursors in laser-writing structures on substrates on which biological cells can be spatially aligned, and (iv) mediators in the fabrication of hierarchical nanostructures that enhance signals in biological Raman spectroscopy. Indeed, microbubbles generated upon laser irradiation of surfaces have many more ramifications than originally thought, with implications in the laser modification of surfaces producing either hydrophilicity or hydrophobicity. Many more possibilities remain to be explored and exploited.

12.
Sci Rep ; 8(1): 16018, 2018 10 30.
Artigo em Inglês | MEDLINE | ID: mdl-30375443

RESUMO

Laser-induced crystallization is emerging as an alternative technique to crystallize biomolecules. However, its applications are limited to specific small molecules and some simple proteins, possibly because of the need to use high-intensity, pulsed lasers and relatively long laser irradiation time. Both these factors tend to denature biological molecules. If the laser-intensity and time required to crystallize biomolecules were to be reduced, laser-induced crystallization may well become of widespread utility. We report here the crystallization of nineteen natural amino acids by a laser-induced method in combination with one of three nucleants: aluminum, coconut coir, and peacock feather barbule. We have utilized a low-power, continuous wave (CW) Nd:YAG laser (λ = 1064 nm). The advantages of our method are (i) the use of very small laser powers (60 mW), and (ii) the ability to obtain diffraction quality crystals within a mere few seconds. For most amino acids our method yields several orders of magnitude reduction in crystallization time. The use of biocompatible nucleants like coir fibres and peacock feather barbules are novel; their non-toxic nature may find broad applicability in rapid crystallization of diverse biological molecules.


Assuntos
Aminoácidos/química , Materiais Biocompatíveis/química , Cristalização , Cristalização/métodos , Lasers de Estado Sólido , Microscopia Eletrônica de Varredura , Solubilidade
13.
Wounds ; 30(3): E25-E28, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29584606

RESUMO

Two siblings, a 19-year-old woman and an 18-year-old man, born to apparently normal parents of second-degree consanguineous marriage, presented to the Department of Dermatology, Sawai Man Singh Medical College Hospital, Jaipur, India, with recurrent skin ulcers of the hands and feet since early childhood. The ulcers were spontaneous, slow to heal, and caused deformities. On initial examination, they were found to have distal sensory loss, predominantly to pain and temperature. The patients were diagnosed with hereditary sensory and autonomic neuropathy of ulceromutilating type (Type 2) based on clinical evidences, nerve studies, and neuropathology. Although clinical features were distinct, due to slow progression of the disease and lack of clinical suspicion, diagnosis was delayed until adulthood when complications developed leading to deformities. Through this report, the authors intend to familiarize readers with this rare disease that can present with trophic ulcers.


Assuntos
Dermatoses do Pé/etiologia , Dermatoses da Mão/etiologia , Neuropatias Hereditárias Sensoriais e Autônomas/complicações , Neuropatias Hereditárias Sensoriais e Autônomas/diagnóstico , Úlcera Cutânea/etiologia , Adolescente , Diagnóstico Tardio , Feminino , Dermatoses do Pé/terapia , Dermatoses da Mão/terapia , Humanos , Masculino , Recidiva , Úlcera Cutânea/terapia , Adulto Jovem
14.
Eur J Anaesthesiol ; 35(5): 390-397, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29373334

RESUMO

BACKGROUND: Hypotension is a common side effect of spinal anaesthesia during caesarean delivery and is associated with maternal and foetal adverse effects. We developed an updated double intravenous vasopressor automated (DIVA) system that administers phenylephrine or ephedrine based on continuous noninvasive haemodynamic monitoring using the Nexfin device. OBJECTIVE: The aim of our present study is to compare the performance and reliability of the DIVA system against Manual Vasopressor Bolus administration. DESIGN: A randomised, double-blind controlled trial. SETTING: Single-centre, KK Women's and Children's Hospital, Singapore. PATIENTS: Two hundred and thirty-six healthy women undergoing elective caesarean delivery under spinal anaesthesia. MAIN OUTCOME MEASURES: The primary outcome was the incidence of maternal hypotension. The secondary outcome measures were reactive hypertension, total vasopressor requirement and maternal and neonatal outcomes. RESULTS: The DIVA group had a significantly lower incidence of maternal hypotension, with 39.3% (46 of 117) patients having any SBP reading less than 80% of baseline compared with 57.5% (65 of 113) in the manual vasopressor bolus group (P = 0.008). The DIVA group also had fewer hypotensive episodes than the manual vasopressor bolus group (4.67 versus 7.77%; P < 0.0001). There was no difference in the incidence of reactive hypertension or the total vasopressor requirement. The DIVA group had less wobble in system performance. Maternal and neonatal outcomes were similar. CONCLUSION: The DIVA system achieved better control of maternal blood pressure after spinal anaesthesia than manual vasopressor bolus administration. TRIAL REGISTRATION: Clinicaltrials.gov identifier: NCT02277730.


Assuntos
Anestesia Obstétrica/métodos , Raquianestesia/métodos , Cesárea/métodos , Hemodinâmica/efeitos dos fármacos , Vasoconstritores/administração & dosagem , Vasoconstritores/uso terapêutico , Adulto , Algoritmos , Automação , Método Duplo-Cego , Feminino , Humanos , Infusões Intravenosas , Cuidados Intraoperatórios , Pessoa de Meia-Idade , Gravidez , Reprodutibilidade dos Testes , Resultado do Tratamento , Adulto Jovem
15.
Int J Trichology ; 9(4): 149-153, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29118518

RESUMO

BACKGROUND: Alopecia areata (AA) is a common, recurrent form of nonscarring alopecia which often presents as circumscribed patches of spontaneous hair loss. The global prevalence of this disease varies from 0.1% to 0.2% in general population and 7-30 cases per 1000 dermatological patients. The etiology of AA still remains uncertain; however, genetic or environmental factor and autoimmunity are claimed responsible for it. Various autoimmune diseases, such as Hashimoto's thyroiditis, diabetes mellitus, vitiligo, and lupus erythematosus, have been reported in association with AA. AIM: The index study was aimed at estimation of serum T3, T4, thyroid-stimulating hormone, and antithyroid peroxidase (TPO) antibodies. MATERIAL AND METHODS: Similar age/sex-matched AA patients and controls (110 in each group). Enhanced chemiluminescence immunoassay for thyroid profile and anti-TPO antibody level estimation in veinous blood sample. OBSERVATIONS: The mean/standard deviation (SD) of T3 was 3.30 ± 0.84 pg/ml in AA while 3.27 ± 0.67 pg/ml in controls (P = 0.302). Serum mean/SD of T4 level was1.23 ± 0.76 ng/dl in AA patients while 1.17 ± 0.34 ng/dl in controls (P = 0.522). The mean/SD of anti-TPO levels in AA patients was 21.52 ± 35.09 while 56.43 ± 140.72 in controls (P = 0.136). LIMITATION: The limitation of this study was moderate number of AA patients and different genotype of study population. CONCLUSION: Occurrence of thyroid dysfunction and evidence of anti-TPO antibodies in AA is rare event in this study population.

16.
Pediatr Dermatol ; 34(5): e241-e244, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28771811

RESUMO

Idiopathic calcinosis cutis is very rare and difficult to treat. Various medical modalities of treatment described with inconsistent results include chelating agents, colchicine, and probenecid. Calcium channel blockers are known to work by inhibiting intracellular entry of calcium. We successfully treated a case of idiopathic calcinosis cutis using oral diltiazem.


Assuntos
Calcinose/tratamento farmacológico , Bloqueadores dos Canais de Cálcio/uso terapêutico , Diltiazem/uso terapêutico , Dermatopatias/tratamento farmacológico , Administração Oral , Adolescente , Cálcio/metabolismo , Humanos , Masculino , Pele/patologia
17.
J Photochem Photobiol B ; 171: 104-116, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28495612

RESUMO

We have utilized Raman tweezers to measure and assign micro-Raman spectra of optically trapped, live red blood cells (RBCs), white blood cells (WBCs) and platelets. Various types of WBCs- both granulocytes, lymphocytes, and their different types have been studied. The Raman bands are assigned to different biomolecules of blood cells. The Raman spectra thus obtained has been enabled detection of ß-carotene in these blood cells, the spectral features of which act as a signature that facilitates experimental probing of the effect of 785nm laser light on different blood cells as a function of incident laser power in the mW range. The spectral changes that we obtain upon laser irradiation indicate that, both haemoglobin as well as the cell membrane sustains damage. In case of lymphocytes and platelets the peaks corresponding to ß-carotene showed drastic changes. Thorough analysis of the spectral changes indicates possibility of free radical induced damage of ß-carotene in lymphocytes and platelets. Among different blood cells, RBCs have a power threshold of only 10mW. The power threshold for other types of blood cells is somewhat higher, but always below about 30mW. These values are likely to serve as useful guides for Raman tweezers based experiments on live cells.


Assuntos
Eritrócitos/efeitos dos fármacos , Raios Infravermelhos , beta Caroteno/farmacologia , Plaquetas/química , Plaquetas/citologia , Plaquetas/efeitos dos fármacos , Plaquetas/efeitos da radiação , Eritrócitos/química , Eritrócitos/citologia , Eritrócitos/efeitos da radiação , Humanos , Linfócitos/química , Linfócitos/citologia , Linfócitos/efeitos dos fármacos , Linfócitos/efeitos da radiação , Análise Espectral Raman
18.
PLoS One ; 12(5): e0176985, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28493906

RESUMO

A diffusion equation has been used to study migration of early humans into the South Asian subcontinent. The diffusion equation is tempered by a set of parameters that account for geographical features like proximity to water resources, altitude, and flatness of land. The ensuing diffusion of populations is followed in time-dependent computer simulations carried out over a period of 10,000 YBP. The geographical parameters are determined from readily-available satellite data. The results of our computer simulations are compared to recent genetic data so as to better correlate the migratory patterns of various populations; they suggest that the initial populations started to coalesce around 4,000 YBP before the commencement of a period of relative geographical isolation of each population group. The period during which coalescence of populations occurred appears consistent with the established timeline associated with the Harappan civilization and also, with genetic admixing that recent genetic mapping data reveal. Our results may contribute to providing a timeline for the movement of prehistoric people. Most significantly, our results appear to suggest that the Ancestral Austro-Asiatic population entered the subcontinent through an easterly direction, potentially resolving a hitherto-contentious issue.


Assuntos
Dinâmica Populacional/história , Ásia , Povo Asiático/genética , Povo Asiático/história , Simulação por Computador , Emigração e Imigração/história , Genética Populacional/história , História Antiga , Humanos
19.
Photochem Photobiol Sci ; 16(6): 870-882, 2017 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-28379273

RESUMO

Laser-induced crystallization is emerging as a promising technique to crystallize biomolecules like amino acids and proteins. The use of external materials as nucleants and novel seeding methods open new paths for protein crystallization. We report here the results of experiments that explore the effect of nucleants on laser-based crystallization of microlitre droplets of small molecules, amino acids, and proteins. The role of parameters like solute concentration, droplet volume, type and size of the nucleant, and laser power, are systematically investigated. In addition to crystallization of standard molecules like NaCl, KCl, and glycine, we demonstrate the crystallization of negatively (l-histidine), and positively (l-aspartic acid) charged amino acids and lysozyme protein. Single crystal X-ray diffraction and Raman spectroscopy studies unequivocally indicate that the nucleants do not alter the molecular structure of glycine, hydrogen bonding patterns, and packing. Localized vaporization of the solvent near the nucleant due to photothermal heating has enabled us to achieve rapid crystallization - within 3 s - at laser intensities of 0.1 MW cm-2, significantly lower than those reported earlier, with both saturated and unsaturated solutions. The outcome of the current experiments may be of utility in tackling various crystallization problems during the formation of crystals large enough to perform X-ray crystallography.

20.
BMC Anesthesiol ; 17(1): 26, 2017 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-28219323

RESUMO

BACKGROUND: The LMA Protector™ is the latest CE marked single use supraglottic airway device. This airway device provides access and functional separation of the respiratory and digestive tracts. There are two ports (male, female ports) to provide suction in the laryngeal region and insertion of the gastric tube. The aim of our study is to assess the ease of use, airway quality, device positioning, airway leak and complications associated with initial clinical experience in LMA Protector™ usage. METHODS: This is an initial investigation of LMA Protector™ airway device. We conducted a preliminary assessment in the anaesthetised women who underwent minor gynaecological procedures with spontaneous ventilation in order to evaluate the performance of the airway device. RESULTS: Insertion was successful on first and second attempts in 23 (88.5%) and 3 (11.5%) respectively. Median [IQR (range)] insertion time was 19 [17-21(14-58)] seconds. Airway leak pressure was 25.5 [23-29(21-30] cmH2O. On fibreoptic examination via the device, vocal cords were visible in all 26 patients. There were no alternative airway use or airway manipulations required during maintenance of anaesthesia. Six patients had sore throat 24 h after procedures and there was no dysphagia or hoarseness. CONCLUSION: This pilot study of the LMA protector shows that the device is easily inserted with fast insertion time, providing a reliable and adequate airway seal. TRIAL REGISTRATION: Clinicaltrials.gov Registration NCT02531256 . Retrospectively registered on August 21, 2015.


Assuntos
Anestesia Geral , Máscaras Laríngeas , Adulto , Desenho de Equipamento , Feminino , Humanos , Intubação Gastrointestinal , Faringite/etiologia , Projetos Piloto
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