RESUMO
Catalysts with V2O5, WO3 and V2O5-WO3 dispersed over TiO2 were synthesized using sol-gel technique and thoroughly characterized by various techniques. The catalysts were evaluated for degradation of ortho-dichloro benzene (o-DCB) in air/helium, a representative probe molecule for polychlorinated dibenzo-para-dioxin and polychlorinated dibenzofuran by employing inâ situ Fourier-transform infrared spectroscopy (FT-IR spectroscopy). Different intermediate species formed on the surface of the TiO2 supported catalysts through of interaction of sorbate molecules with the lattice and/or gaseous oxygen were investigated in detail. Analysis of vibrational bands, observed during sorption of o-DCB and o-DCB-air mixture as a function of temperature over these catalysts, delineated the role of surface intermediate species such as phenolate, enolates, maleates, carboxylates, carbonates in mineralization of o-DCB. Nature and stability of intermediate species, found to be different over these catalysts, were able to elucidate the catalytic activity trend.
RESUMO
BACKGROUND: Obesity is associated with greater oxytocin requirement during labor induction or augmentation. There are scant data exploring the intra-operative requirement during cesarean delivery in patients with obesity, and none comparing it with those without obesity. We evaluated the minimum effective dose (ED90) of an oxytocin infusion to achieve adequate uterine tone during cesarean delivery in patients with and without obesity. METHODS: Patients (body mass indexâ¯≥30â¯kg/m2 represented patients with obesity) undergoing cesarean delivery using subarachnoid block were included. This prospective dual-arm dose-finding study used a 9:1 biased sequential allocation design. Oxytocin infusion was initiated at 13â¯IU/h at cord clamping in the first patient of each group. Uterine tone was graded as satisfactory or unsatisfactory by the obstetrician four minutes after initiation of the infusion. The dose of oxytocin infusion for subsequent patients was determined according to the response of the previous patient in the group. Oxytocin-associated side effects were evaluated. Dose-response data for the groups was evaluated using log-logistic function and ED90 estimates derived from fitted equations using the delta method. RESULTS: The ED90 of oxytocin was significantly higher for patients with obesity (nâ¯=â¯40) compared with those without obesity (nâ¯=â¯40) [25.7â¯IU/h, 95% CI 18.6 to 32.9) vs. 16.6â¯IU/h, 95% CI 14.9 to 18.3)]; relative ratio 1.55 [95% CI 1.09 to 2.01] (Pâ¯=â¯0.019). CONCLUSIONS: Patients with obesity require a higher intra-operative oxytocin infusion dose rate to achieve a satisfactorily contracted uterus after fetal delivery when compared with patients without obesity.
Assuntos
Ocitócicos , Ocitocina , Gravidez , Feminino , Humanos , Ocitocina/uso terapêutico , Ocitócicos/uso terapêutico , Ocitócicos/efeitos adversos , Estudos Prospectivos , Cesárea/métodos , Obesidade/complicaçõesRESUMO
BACKGROUND: Patients with pre-eclampsia require smaller vasopressor doses compared with those with normotension for management of post-spinal hypotension during caesarean section. However, the literature has little evidence as to the phenylephrine dose required for patients with pre-eclampsia. METHODS: Fifty patients, with either pre-eclampsia or normotension, and developing post-spinal hypotension during caesarean section under spinal anaesthesia, were studied. Women in both groups did not receive prophylactic vasopressors. The first patient in each group received phenylephrine 50⯵g to treat the first episode of hypotension, defined as fall of systolic blood pressure ≥20% from baseline or an absolute value <100â¯mmHg. If hypotension was corrected within one minute it was considered a 'success'. The doses for the subsequent patients were determined by responses to all previous patients, according to a variation of Narayana's rule for the up-down sequential allocation method. RESULTS: The 95% effective dose (ED95) and 50% effective dose (ED50) of phenylephrine was 41.7⯵g (95% CI 33.8 to 49.6⯵g) and 29.1⯵g (95% CI 26.0 to 32.2⯵g) respectively in the pre-eclampsia group, and 64.9⯵g (95% CI 54.1 to 75.7⯵g) and 47.3⯵g (95% CI 39.7 to 54.9⯵g) respectively in the normotensive group. The proportionate reduction in phenylephrine dose ranged from 33% (95% CI 18 to 44%) to 40% (95% CI 19 to 52%). CONCLUSION: Patients with pre-eclampsia may need a 33% to 40% reduction in the first phenylephrine bolus dose, compared with patients with normotension, for the treatment of the first episode of post-spinal hypotension.
Assuntos
Anestesia Obstétrica , Raquianestesia , Hipotensão , Pré-Eclâmpsia , Humanos , Feminino , Gravidez , Fenilefrina/uso terapêutico , Pré-Eclâmpsia/tratamento farmacológico , Cesárea/métodos , Anestesia Obstétrica/efeitos adversos , Hipotensão/tratamento farmacológico , Hipotensão/etiologia , Hipotensão/prevenção & controle , Vasoconstritores/uso terapêutico , Raquianestesia/efeitos adversos , Raquianestesia/métodos , Método Duplo-CegoRESUMO
Herein, using in situ generated solvated electrons in the reaction media, a highly time-efficient, one-pot green approach has been employed to synthesize palladium (Pd) nanoparticles (NPs) coated with a molecular assembly of α-cyclodextrin (α-CD). The appearance of a shoulder peak at 280 nm in the UV-Vis absorption spectra indicated the formation of Pd NPs, which was further confirmed from their cubic phase XRD pattern. The nanomorphology varied considerably as a function of the dose rate, wherein sphere-shaped NPs (average size â¼ 7.6 nm) were formed in the case of high dose rate electron-beam assisted synthesis, while nanoflakes self-assembled to form nanoflower-shaped morphologies in a γ-ray mediated approach involving a low dose rate. The formation kinetics of NPs was investigated by pulse radiolysis which revealed the formation of Pd-based transients by the solvated electron-induced reaction. Importantly, no interference of α-CD was observed in the kinetics of the transient species, rather it played the role of a morphology directing agent in addition to a biocompatible stabilizing agent. The catalytic studies revealed that the morphology of the NPs has a significant effect on the reduction efficiency of 4-nitrophenol to 4-aminophenol. Another important highlight of this work is the demonstration of the morphology-dependent anticancer efficacy of Pd NPs against lung and brain cancer cells. Notably, flower-shaped Pd NPs exhibited significantly higher cancer cell killing as compared to spherical NPs, while being less toxic towards normal lung fibroblasts. Nonetheless, these findings show the promising potential of Pd NPs in anticancer treatment.
Assuntos
Ciclodextrinas , Nanopartículas Metálicas , Paládio , Elétrons , CatáliseRESUMO
Ankle-foot orthotics need ideal specification of being light-weight, high strength, tough, stiff, and durable. Reinforced polypropylene (PP) composites with enhanced mechanical properties are the most favorable materials being used in this field, but still, it is challenging to achieve balanced blend of strength and toughness in the composites. The present study thus aims to achieve the challenging task of simultaneous improvement in stiffness and toughness in reinforced PP composites exploring the synergistic reinforcement effect of glass fibers (GFs) and nano silica (SiO2) as multiscale fillers and ethylene propylene diene monomer (EPDM) as impact modifier. EPDM is used as toughness modifier, addressing the brittle behavior, but at the cost of the strength of the polymer. Combined use of micro and nanofillers as reinforcement in toughened polypropylene provides a potential approach to balance the strength while maintaining the toughness. GFs could offer high strength and nanofillers offer ductile fracture to the material. PP, PP/GF, PP/EPDM/GF composites and PP/EPDM/GF/SiO2 nanocomposites are fabricated through melt blending technique and are characterized through SEM, mechanical evaluation, nanoindentation and dynamic mechanical analysis. Mechanical properties are evaluated in accordance with ASTM standards. PP/EPDM/GF/SiO2 nanocomposites exhibits remarkable enhancement in Tensile strength, tensile modulus, impact strength and percent elongation at break by 49 MPa (55% increase over PP), 2450 MPa (145% increase), 145 J/m (13% increase) and 156% (160% increase) respectively. The exceptional improvement in reduced modulus and hardness reveals good interfacial properties. Loss factor decrement reveals elastic behavior of nanocomposites suitable for thermoforming of nanocomposites for orthotic device fabrication.
Assuntos
Nanocompostos , Dióxido de Silício , Polipropilenos , Teste de Materiais , EtilenosRESUMO
Continuous improvement in the living standards of developing countries, calls for an urgent need of high quality meat and dairy products. The farm animals have a micro-ecosystem in gastro-intestinal tract, comprising of a wide variety of flora and fauna which converts roughages and agricultural byproducts as well as nutrient rich concentrate sources into the useful products such as volatile fatty acids and microbial crude proteins. The microbial diversity changes according to composition of the feed, host species/breed and host's individual genetic makeup. From culture methods to next-generation sequencing technologies, the knowledge has emerged a lot to know-how of microbial world viz. their identification, enzymatic activities and metabolites which are the keys of ruminant's successful existence. The structural composition of ruminal community revealed through metagenomics can be elaborated by metatranscriptomics and metabolomics through deciphering their functional role in metabolism and their responses to the external and internal stimuli. These highly sophisticated analytical tools have made possible to correlate the differences in the feed efficiency, nutrients utilization and methane emissions to their rumen microbiome. The comprehensively understood rumen microbiome will enhance the knowledge in the fields of animal nutrition, biotechnology and climatology through deciphering the significance of each and every domain of residing microbial entity. The present review undertakes the recent investigations regarding rumen multi-omics viz. taxonomic and functional potential of microbial populations, host-diet-microbiome interactions and correlation with metabolic dynamics.
Assuntos
Microbiota , Rúmen , Animais , Rúmen/metabolismo , Fazendas , Multiômica , Dieta/veterinária , Ração AnimalRESUMO
OBJECTIVE: To study the utility of Galactomannan (GM) antigen as a screening marker for diagnosing invasive pulmonary aspergillosis (IPA) in coronavirus disease 2019 (COVID-19) patients. PATIENTS AND METHODS: The serum samples from patients with severe COVID-19 diseases admitted to the Critical Care Unit were collected on the 5th day of admission for GM screening. The samples were analysed by enzyme linked immune sorbent assay (ELISA) and GM index of more than 1 was considered as positive. All GM positive patients were serially followed until discharge or death. RESULTS: The GM was raised in serum of 12 out of 38 patients, indicating an incidence of possible COVID-19 associated IPA (CAPA) in 31.57% of patients. The median age of these CAPA patients was 56.5 years, males were significantly more affected than females. The inflammatory marker serum ferritin was raised in all 12 patients (median value of 713.74 ng/ml), while IL-6 was raised in 9 patients (median value of 54.13 ng/ml). None of these patients received antifungals. Their median length of hospital stay was 20 days (IQR: 12, 34 days). All these patients succumbed to the illness. CONCLUSIONS: The serum GM appears to be sensitive diagnostic tool to identify early IPA in COVID-19 patients and pre-emptive antifungal therapy could play a role in salvaging these patients.
Assuntos
COVID-19/diagnóstico , Galactose/análogos & derivados , Aspergilose Pulmonar Invasiva/diagnóstico , Mananas/sangue , Adulto , Idoso , COVID-19/complicações , COVID-19/virologia , Ensaio de Imunoadsorção Enzimática , Feminino , Galactose/sangue , Humanos , Interleucina-6/metabolismo , Aspergilose Pulmonar Invasiva/complicações , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Estudos Prospectivos , SARS-CoV-2/isolamento & purificação , Fatores SexuaisRESUMO
In legumes, waterlogging is a major detrimental factor leading to huge yield losses. Generally, legumes lack tolerance to submergence, and conventional breeding to develop tolerant varieties are limited due to the lack of tolerant germplasm and potential target genes. Moreover, our understanding of the various signalling cascades, their interactions and key pathways induced during waterlogging is limited. Here, we focus on the role of two important plant signalling molecules, viz. hydrogen sulphide (H2 S) and nitric oxide (NO), during waterlogging stress in legumes. Plants and soil microbes produce these signalling molecules both endogenously and exogenously under various stresses, including waterlogging. NO and H2 S are known to regulate key physiological pathways, such as stomatal closure, leaf senescence and regulation of numerous stress signalling pathways, while NO plays a pivotal role in adventitious root formation during waterlogging. The crosstalk between H2 S and NO is synergistic because of the resemblance of their physiological effects and proteomic functions, which mainly operate through cysteine-dependent post-translational modifications via S-nitrosation and persulfidation. Such knowledge has provided novel platforms for researchers to unravel the complexity associated with H2 S-NO signalling and interactions with plant stress hormones. This review provides an overall summary on H2 S and NO, including biosynthesis, biological importance, crosstalk, transporter regulation as well as understanding their role during waterlogging using 'multi-omics' approach. Understanding H2 S and NO signalling will help in deciphering the metabolic interactions and identifying key regulatory genes that could be used for developing waterlogging tolerance in legumes.
Assuntos
Fabaceae , Óxido Nítrico , Produtos Agrícolas , Fabaceae/metabolismo , Óxido Nítrico/metabolismo , Melhoramento Vegetal , Proteômica , Estresse Fisiológico/fisiologiaRESUMO
BACKGROUND: Transsphenoidal surgery (TSS) remains the treatment of choice for non-functioning pituitary macroadenomas (NFPMA). The value of measuring tumour volumes before and after surgery, and its influence on endocrine outcomes and further treatment of the residual or recurrent tumour are unknown. METHODS: Data from patients who underwent endoscopic TSS for a NFPMA (2009-2018) in a UK tertiary centre were analysed for pre- and post-operative endocrine and surgical outcomes. RESULTS: Of 173 patients with NFPMA, 159 (61% male) were treatment naïve. At presentation, 76.2% (77/101) had ≥1 pituitary axis deficit. Older age (p = 0.002) was an independent predictor for multiple hormonal deficiencies. Preoperative tumour volume did not correlate with degree of hypopituitarism. Postoperative tumour volume and extent of tumour resection were not predictive of new onset hypopituitarism. Hormonal recovery was observed in 16 patients (20.8%) with impaired pituitary function, with the greatest recovery in the hypothalamic-pituitary-adrenal axis (21.2%, 7/33). A larger residual tumour volume was predictive of adjuvant radiotherapy (3.40 vs. 1.24 cm3, p = 0.005) and likelihood for repeat surgery (5.40 vs. 1.67cm3, p = 0.004). CONCLUSION: Pre- and post-operative NFPMA volumes fail to predict the number of pituitary hormone deficits, however, greater post-operative residual volumes increase the likelihood of further intervention to control tumour growth.
Assuntos
Adenoma/cirurgia , Endoscopia/efeitos adversos , Recidiva Local de Neoplasia/cirurgia , Neoplasia Residual/cirurgia , Hormônios Hipofisários/sangue , Neoplasias Hipofisárias/cirurgia , Complicações Pós-Operatórias/patologia , Adenoma/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/patologia , Neoplasia Residual/patologia , Neoplasias Hipofisárias/patologia , Complicações Pós-Operatórias/sangue , Complicações Pós-Operatórias/etiologia , Prognóstico , Estudos Retrospectivos , Adulto JovemRESUMO
The objective of this study was to evaluate the effects of synbiotic formulation of Cichorium intybus root powder (C) with Lactobacillus acidophilus NCDC15 (LA) and Lactobacillus reuteri BFE7 (LR) on growth performance in Murrah buffalo calves via monitoring selective gut health indices. Twenty-four Murrah buffalo calves of 5-7 days old and 33 ± 2.0 kg of body weight were distributed randomly into three groups adopting complete randomized design (CRD) as follows: (1) group I served as control (CON) provided with a basal diet alone; (2) group II supplemented with synbiotic formulation of 200 mL L. acidophilus NCDC15 fermented milk with 8 g of Cichorium intybus root powder (LAC) along with basal diet; (3) group III supplemented with synbiotic formulation of 200 mL L. reuteri BFE7 fermented milk with 8 g of Cichorium intybus root powder (LRC) along with basal diet. The final body weight (BW), average dry matter intake (DMI) and structural body measurements were significantly increased (P < 0.05) in LAC and LRC groups by synbiotic as compared to the CON. No effect was registered on apparent nutrient digestibility coefficient of various nutrients in supplemented groups. Faecal score was reduced by the supplementation of synbiotic being lowest in LRC followed by LAC and CON. Calves supplemented synbiotic showed lower (P < 0.05) faecal pH and ammonia with a concomitant increase in faecal lactate levels and faecal short chain fatty acids (SCFA) as compared to control. The faecal Lactobacillus and Bifidobacterium population was increased (P < 0.05) in synbiotic fed groups as compared to control. Additionally, coliform and clostridia count was decreased (P < 0.05) in treatment groups compared to CON. Overall, it may be concluded that synbiotic supplementation was effective in improving the growth performance in Murrah buffalo calves via altering selective gut health indices.
Assuntos
Cichorium intybus , Limosilactobacillus reuteri , Simbióticos , Ração Animal/análise , Animais , Búfalos , Dieta/veterinária , Lactobacillus acidophilus , PósRESUMO
OBJECTIVE: This study aimed to investigate the possible association between recurrent facial nerve palsy and migraines. METHOD: This study was a prospective case series with a two-year follow-up at an academic, tertiary referral centre and included patients with at least four episodes of recurrent lower motor neuron facial nerve palsy. All patients underwent standardised diagnostic tests. RESULTS: Four patients fulfilled the inclusion criteria. The patients were all female with an average age at presentation of 40.75 years (range, 33-60 years) and an average age at the initial episode of 14 years (range, 12-16 years). The number of episodes varied between six and nine. All patients had at least one episode of facial nerve palsy on the contralateral side. Two patients were diagnosed and treated for migraine with aura remaining asymptomatic following prophylactic medication for migraines. CONCLUSION: The results raise the possibility of an association between recurrent facial nerve palsy and migraines. Prospective studies in patients with even fewer episodes of facial nerve palsy could shed more light on this association.
RESUMO
The dominant intensity of parity-forbidden intra-4f transitions of europium(III) over O â Eu charge-transfer band (CTB) intensity is against common perceptions, yet this trend is observed in many germanate hosts and has not been rationalized so far. In search of a plausible explanation for this unusual trend, present work reports an experimental and theoretical investigations in conjunction on two sibling germanate host, namely, Y2GeO5 and Y2Ge2O7 having dopant Eu3+ in their respective YO7 polyhedra. Whereas for Y2GeO5:Eu3+, the CTB is more intense than the intra-4f transitions in the excitation spectrum, in the case of Y2Ge2O7:Eu3+, the relative intensities of CTB and intra-4f transitions are reversed. Comparative structural analysis reveals that Eu3+ present in YO7 of Y2GeO5 has a greater number of tetra-coordinated oxygen (Otetra) and yttrium atom as first and second neighbors, respectively (Eu3+-Otetra-Y3+ linkages). Conversely, in Y2Ge2O7 host, the Eu3+ ion mostly has tricoordinated oxygen (Otri) as its nearest neighbor and germanium ions next to Otri (Eu3+-Otri-Ge4+ linkage). Theoretical calculations reveal that while Y2GeO5:Eu has Otetra(4Y) dominating at the Fermi level and the 4f state of Eu3+ remains inert toward mixing, in Y2Ge2O7:Eu, the Fermi level has major contribution from Otri(2Y + 1Ge) with significant mixing with 4f states of Eu. The dominant control of Eu3+-Otri-Ge4+ linkages in geometrical and electronic structure of Y2Ge2O7:Eu owing to the GeO4 surrounding has been attributed to relative poor intensity of O â Eu CTB. Siege of Eu3+ by GeO4 and subsequent occurrence of Eu3+-Otri-Ge4+ linkages play a dual role: First, it induces electronic rigidity to hinder excitation of electron at bridging (Otri) oxygen by highly charged small Ge4+ cation; second, the covalent character in Eu-O bond is achieved by intermixing of Eu's 4f and Otri 2p orbital which facilitates relaxing of the parity-selection rule thus enhancing the probability of intra-4f transitions. The inferences drawn remain valid when extrapolated to other inorganic oxides having EuOx polyhedra surrounded by covalent units like PO4, SiO4, etc. and have a prevailing number of low-coordinated oxygen atoms and highly charged small cation in the first and second coordination shells, respectively. The optical basicity concept is also found to endorse our explanation. These remarkable generic inferences will pave the rational way for designing efficient phosphors for solid-state lighting.
RESUMO
BACKGROUND: Among the multitudinous etiologies of pancreatitis, primary hyperparathyroidism (PHPT) is rarely associated with pancreatitis. However, the cause and effect relationship between the two still evokes controversy. We aimed to study and characterize the nature of pancreatic disease in PHPT. METHODS: A retrospective single-center study was carried out in North India over a period of 1 year (June 2015 to May 2016). All patients with pancreatitis were included. In patients with high calcium levels, Intact Parathyroid Hormone (iPTH) by Radioimmunoassay (RIA) and an Technetium 99m Sestamibi scintigraphy (MIBI-Tc-99m) scan were performed. RESULTS: During the study period, 70 patients with pancreatitis were admitted to our hospital (53 with acute pancreatitis [AP] and 17 with chronic pancreatitis [CP]). Of them, 5 patients (9.4%) were detected to have PHPT. The mean age of patients was 30.4 years (20-49 years) with 3 males and 2 females, including 1 pregnant female (29th week of gestation). Contrast enhanced computed tomography (CECT) abdomen was performed in 4 cases (excluding 1 pregnant patient) with mean Computed tomography severity index (CTSI) of 4.7 (2-8). Four patients were detected to have increased uptake in one of the parathyroid glands, and the fifth patient had an ectopic parathyroid uptake in the mediastinum. All the resected samples were identified as parathyroid adenoma on histology. The patients were followed up for 1 year with no reported recurrence of symptoms. CONCLUSION: The data suggest an association between pancreatitis (both acute and chronic) and hypercalcemia due to PHPT. A high calcium value during AP or CP should always draw suspicion and warrants corresponding investigations in search of endocrine or malignant cause.
RESUMO
BACKGROUND: Phenylephrine, although considered the vasopressor of choice, can cause reflex bradycardia and a fall in cardiac output. Norepinephrine, due to its direct positive chronotropic and reflex negative chronotropic actions, is expected to overcome this problem. However, limited information about its effective dose for management of post-spinal hypotension, and its potency compared to phenylephrine, is available. METHODS: One hundred consecutive patients who developed post-spinal hypotension were treated with a predetermined dose of either phenylephrine or norepinephrine. Correction of hypotension after one minute was considered 'success'. The starting dose for the first patient and testing interval (the incremental or decremental dosing) were 100⯵g and 10⯵g in the phenylephrine group, and 6⯵g and 0.5⯵g in the norepinephrine group. Doses for subsequent patients were determined by the responses of previous patients according to the Narayana rule for up-down sequential allocation. ED95 and ED50 of phenylephrine and norepinephrine boluses and their potency ratio were calculated. RESULTS: Using Probit analysis, ED95 and ED50 values were 43.1⯵g (95% CI 39.5 to 65.0⯵g) and 33.2⯵g (95% CI 5.1 to 37.0⯵g) for phenylephrine, and 3.7⯵g (95% CI 3.5 to 4.7⯵g) and 3.2⯵g (95% CI 1.8 to 3.4⯵g) for norepinephrine. The relative potency ratio of norepinephrine and phenylephrine was 11.3 (95% CI 8.1 to 16.9). CONCLUSION: Based on the results of this study, norepinephrine is about 11 times more potent than phenylephrine. When used as bolus doses for treatment of hypotension, 100⯵g phenylephrine should be approximately equivalent to 9⯵g norepinephrine.
Assuntos
Anestesia Obstétrica/efeitos adversos , Raquianestesia/efeitos adversos , Cesárea , Hipotensão/tratamento farmacológico , Norepinefrina/farmacologia , Fenilefrina/farmacologia , Agonistas de Receptores Adrenérgicos alfa 1/farmacologia , Agonistas alfa-Adrenérgicos/farmacologia , Adulto , Método Duplo-Cego , Procedimentos Cirúrgicos Eletivos , Feminino , Humanos , Hipotensão/etiologia , Gravidez , Resultado do TratamentoRESUMO
BACKGROUND: This study aims to investigate radiation beam geometry of Cyberknife beam and change in dosimetric characteristics of six megavoltage (6MV) flattening filter free (FFF) beam after passing through high density cadmium free compensator alloy. MATERIAL AND METHODS: In this experimental study, changes in FFF beam dosimetric characteristics after passing through compensator alloy was measured. Transmitted intensity of FFF beam was measured in air by an ion chamber at a source to detector distance (SDD) of 800mm. Extended SDD measurement also has been performed at a distance of 1270mm to analyze scattering due to compensator. Linear attenuation coefficient (µeff) was measured for cadmium free compensator alloy using simple exponential attenuation model. Percentage depth doses (PDDs) have been measured by a radiation field analyzer with compensator material to observe the beam hardening and change in surface doses and depth doses. RESULTS: Linear attenuation coefficient of compensator alloy was measured 0.042 (Standard Deviation ±0.00099) mm-1 and it was found that there is no change with increase in collimator size. Even after increasing distance source from detector, µeff has no change. PDDs were found to increase with thickness of compensator. PDD from a 60mm collimator size increased by 5% and 6% at a depth of 100mm and 200mm, respectively in water. PDD also increased with collimator size less significantly. Surface dose was found to decrease with increase in compensator thickness. CONCLUSION: Cyberknife beam has been found to be narrow beam geometry. FFF beam contains lesser scattered photons. Presence of high density compensator filters out the soft x-ray photon causes significant dosimetric changes.
RESUMO
BACKGROUND: There are few data regarding acute kidney injury in critically-ill obstetric patients. A combination of urinary cell cycle arrest markers, tissue inhibitor of metalloproteinase-2 (TIMP-2) and insulin-like growth factor binding protein7 (IGFBP7), is validated for the early prediction of acute kidney injury in non-obstetric patients. METHODS: We evaluated the epidemiology of acute kidney injury in critically-ill obstetric patients and the role of the biomarker combination in predicting acute kidney injury and mortality. Acute kidney injury, its severity and risk factors, were assessed using Kidney Disease: Improving Global Outcomes (KDIGO) guidelines during the intensive care unit stay. An ELISA technique measured TIMP-2 and IGFBP7 in urine samples collected at the time of admission there. RESULTS: Results for 66 patients showed an overall incidence of acute kidney injury of 40/66 (61%), with 50%, 10% and 40% being in stage 1, 2 and 3 respectively. Patients with acute kidney injury showed significantly greater sepsis and shock; longer stay and higher mortality during intensive care (33% vs 0%) and in hospital (38% vs 0%) compared to those without (Pâ¯<0.05). The area-under-the receiver operating characteristics curve was <0.5 for urinary [TIMP-2]·[IGFBP7] as a predictor of kidney injury and mortality (Pâ¯>0.05). CONCLUSIONS: Acute kidney injury is common in critically-ill obstetric patients, increasing mortality and duration of hospitalization. It was significantly more common in patients with septic shock. Previously validated results of urinary [TIMP-2]·[IGFBP7] that successfully predict early acute kidney injury or mortality are not applicable to obstetric patients.