Soil carbon determination by high temperature combustion - A comparison with dichromate oxidation procedures and the influence of charcoal and carbonate carbon on the measured value

The measurement of organic carbon in soils has traditionally used dichromate oxidation procedures including the Wakley and Black and the Heanes methods. The measurement of carbon in soils by high temperature combustion is now widely used providing a rapid automated procedure without the use of toxic chemicals. This procedure however measures total carbon thus requiring some means of correction for soil samples containing carbonate and charcoal forms of carbon. This paper examines the effects of known additions of charcoal to a range of soil types on the results obtained by the Walkley and Black, Heanes and combustion methods. The results show, that while the charcoal carbon does not react under Walkley and Black conditions, some proportion does so with the Heanes method. A comparison of six Australian Soil and Plant Analysis Council reference soil samples by the three methods showed good agreement between the Heanes method, the combustion method and only slightly lower recoveries by the Walkley and Black procedure. Carbonate carbon will cause an overestimation of soil organic carbon by the combustion method thus requiring a separate determination of carbonate carbon to be applied as a correction. This work shows that a suitable acid pre-treatment of alkaline soils in the sample boats followed by a drying step eliminates the carbonate carbon prior to combustion and the need for an additional measurement. The measurement of carbon in soils by high temperature combustion in an oxygen atmosphere has been shown to be a rapid and reliable method capable of producing results in good agreement with one of the established dichromate oxidation procedures.

Effects of postnatal protein malnutrition on learning and memory procedures

Protein malnutrition induces structural, neurochemical and functional changes in the central nervous system leading to alterations in cognitive and behavioral development of rats. The aim of this work was to investigate the effects of postnatal protein malnutrition on learning and memory tasks. Previously malnourished (6% protein) and well-nourished rats (16% protein) were tested in three experiments: working memory tasks in the Morris water maze (Experiment I), recognition memory of objects (Experiment II), and working memory in the water T-maze (Experiment III). The results showed higher escape latencies in malnourished animals in Experiment I, lower recognition indexes of malnourished animals in Experiment II, and no differences due to diet in Experiment III. It is suggested that protein malnutrition imposed on early life of rats can produce impairments on both working memory in the Morris maze and recognition memory in the open field tests.

Follow-up of endovascular treatment of direct carotid-cavernous fistulas

Direct carotid-cavernous fistula (CCF) is a direct communication between the internal carotid artery (ICA) and the cavernous sinus. Some patients treated with detachable balloons develop pseudoaneurysms or present with a true aneurysm recanalization in the cavernous ICA with poorly known long-term radiological and clinical progression. The objective of the present study was to evaluate the long-term clinical and radiological progression of patients treated with detachable balloons. The present study evaluated 13 patients previously treated for direct CCF by an endovascular approach. The follow-up period ranged between 19 and 128 months. Ophthalmological evaluation demonstrated alterations in eight patients (61.5%). All of these alterations were already present from the moment of the treatment and displayed no signs of progression. Cranial magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) were performed in all patients, and 11 pseudoaneurysms were demonstrated in ten of the 11 patients in whom ICA patency had been preserved. Five patients were submitted for cerebral digital subtraction angiography (DSA) to characterize the pseudoaneurysms previously observed on MRA studies, with no significant differences in morphology, size, aneurismal neck, and number of lesions. Endovascular treatment of direct CCF with detachable balloons has been shown to be a long-term effective and stable therapeutic method. The authors found asymptomatic pseudoaneurysms in 91% of cases where the ICA patency was preserved. MRI and MRA demonstrated an accuracy similar to that of DSA in the diagnosis of pseudoaneurysms of cavernous ICA.

Endovascular Treatment for Chronic Arteriovenous Fistula Between Renal Artery and Inferior Vena Cava: Image in Vascular Surgery

Arteriovenous fistula involving renal artery and inferior vena cava are rare. We report the case of a 47-year-old woman with a chronic arteriovenous fistula between right renal artery and inferior vena cava due to a penetrating trauma. Another finding was a vena cava aneurysm caused by the fistula. The patient was successfully treated with a covered stent in the renal artery. Diagnosis and postoperative control have been documented with CT scan. Endovascular techniques may be effective and minimally invasive option for treatment and renal preservation in renal-cava arteriovenous fistulae.

Limb Salvage Using Bypass to the Perigeniculate Arteries

Objective: To describe bypass to perigeniculate vessels for limb salvage. Design: Retrospective cohort study. Material and methods: Between 1995 and 2009, 47 bypass procedures to perigeniculate collateral arteries were performed in 46 patients (15 women, 31 men; median age, 68 years). All patients presented with critical ischaemia (tissue loss in 87.5%, rest pain in 12.5%). Mean ankle brachial index was 0.27 +/- 0.17. The site of distal anastomosis was the descending genicular artery (DGA) in 23 bypasses (1 bilateral) and the medial sural artery (MSA) in 24. Proximal anastomosis was to the external iliac artery in 2 cases, common femoral artery in 23 cases, superficial femoral artery in 8 cases, deep femoral artery in 8 cases, above-knee poplitaeal artery in 2 cases, and previous graft in 4 cases. Results: There were four deaths during the immediate postoperative period. Mean follow-up duration was 27 months. Ten patients required major amputation. Mean ankle brachial index post-operatively was 0.60 +/- 0.21. At 3 years, primary patency was 74.7 +/- 7%, secondary patency was 83.4 +/- 8%, and the limb salvage and survival rates were 73.5 +/- 7% and 77.4 +/- 7%, respectively. Conclusion: Bypass to perigeniculate arteries is a viable treatment option for critical limb ischaemia in selected patients. (C) 2011 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

Measurement of radiation dose received by the hands and thyroid of staff performing gridless fluoroscopic procedures in children

The aim of this study was to confirm that the radiation doses received by attendants who manually restrain infants during fluoroscopic procedures are low. Doses to the hands and neck of three radiologists and three nurses performing or assisting at all the fluoroscopic procedures in a children's hospital were measured for 1 month using thermoluminescent dosemeters. All fluoroscopy on children at this hospital is performed without an antiscatter grid. Total doses for the neck ranged from 20 to 50 mu Sv per week and for hands from 40 to 210 mu Sv per week. These doses were shared by the three radiologists and the three nurses. Individual doses received per staff member are very small when compared with the doses received by interventional radiology staff. Doses received by staff in this study were of the order of 5% of the limit advised by the National Health and Medical Research Council of Australia (NHMRC) for radiation workers. Nurses received larger doses than radiologists and steps will be taken to reduce this dose further.

Thermogravimetric analytical procedures for determining reactivities of chars from New Zealand coals

Tightly constrained thermogravimetric experimental procedures (particle size < 212 mu m, sample mass 15.5 mg, CO2 reactant gas, near isothermal conditions) allow the reactivity of chars from high volatile New Zealand coals to be determined to a repeatability of +/-0.07 h(-1) at 900 degrees C and +/-0.5 h(-1) at 1100 degrees C. The procedure also provides proximate analyses information and affords a quick (< 90 min) comparison between different coal types as well as indicating likely operating conditions and problems associated with a particular coal or blend. A clear difference is evident between reactivities of differing New Zealand coal ranks. Between 900 and 1100 degrees C, bituminous coals increase thirtyfold in reactivity compared with fourfold for subbituminous, with the latter being three to five times greater in reactivity at higher temperature. (C) 1997 Elsevier Science B.V.

Reprocessing and reuse of single-use medical devices used during hemodynamic procedures in Brazil: A widespread and largely overlooked problem

Background. Several medical devices used during hemodynamic procedures, particularly angiographic diagnostic and therapeutic cardiac catheters, are manufactured for single use only. However, reprocessing and reuse of these devices has been reported, to determine the frequency of reuse and reprocessing of single-use medical devices used during hemodynamic procedures in Brazil and to evaluate how reprocessing is performed. Design. National survey, conducted from December 1999 to July 2001. Methods. Most of the institutions affiliated with the Brazilian Society of Hemodynamic and Interventional Cardiology were surveyed by use of a questionnaire sent in the mail. Results. The questionnaire response rate was 50% (119 of 240 institutions). Of the 119 institutions that responded, 116 (97%) reported reuse of single-use devices used during hemodynamic procedures, and only 26 (22%) reported use of a standardized reprocessing protocol. Cleaning, flushing, rinsing, drying, sterilizing and packaging methods varied greatly and were mostly inadequate. Criteria for discarding reused devices varied widely. Of the 119 institutions that responded, 80 (67%) reported having a surveillance system for adverse events associated with the reuse of medical devices, although most of these institutions did not routinely review the data, and only 38 (32%) described a training program for the personnel who reprocessed single-use devices. Conclusions. The reuse of single-use devices used during hemodynamic procedures was very frequent in hospitals in Brazil. Basic guidance on how to reuse and reprocess single-use medical devices is urgently needed, because, despite the lack of studies to support reusing and reprocessing single-use medical devices, such devices are necessary in limited-resource areas in which these practices are current.

Percutaneous Transatrial Access to the Pericardial Space for Epicardial Mapping and Ablation

Background-Puncture of the atrial appendage may provide access to the pericardial space. The aim of this study was to evaluate the feasibility of epicardial mapping and ablation through an endocardial transatrial access in a swine model. Methods and Results-An 8-F Mullins sheath was used to perforate the right (n=16) or left (n=1) atrial appendage in 17 pigs (median weight, 27.5 kg; first and third quartiles [Q1, Q3], 25.2, 30.0 kg). A 7-F ablation catheter was introduced into the pericardial space to perform epicardial mapping and deliver radiofrequency pulses on the atria. The pericardial space was entered in all 17 animals. In 15 (88%) animals, there was no hemodynamic instability (mean blood pressure monitoring, initial median, 80 mm Hg; Q1, Q3, 70, 86 mm Hg; final median, 88 mm Hg; Q1, Q3, 80, 96 mm Hg; P=0.426). In these 15, a mild hemorrhagic pericardial effusion was identified and aspirated (median, 20 mL; Q1, Q3, 15, 30 mL) during the procedure, and postmortem gross analysis revealed that the atrial perforation was closed in these animals. In 2 (12%) of the 17 animals, there was major pericardial bleeding with hemodynamic collapse. On gross examination, it was found that pericardial space was accessed through right ventricular perforation in 1 animal and the tricuspid annulus in the other. After the initial study, we used an occlusion device in 3 other animals to attempt to seal the puncture (2 at the right atrial appendage and 1 at the right ventricle). These 3 animals had no significant pericardial bleeding. Conclusions-Transatrial endovascular right atrial appendage puncture may provide a potential alternative route for pericardial access. Further studies are needed to evaluate its safety with longer and more-complex procedures before being applied in clinical settings. (Circ Arrhythm Electrophysiol. 2011;4:331-336.)

Effect of Antioxidants During Bovine In Vitro Fertilization Procedures on Spermatozoa and Embryo Development

Increased amounts of reactive oxygen species (ROS) during in vitro fertilization (IVF) may cause cytotoxic damage to gametes, whereas small amounts of ROS favour sperm capacitation. The aim of this study was to investigate the effect of antioxidants [50 mu M beta-mercaptoethanol (beta-ME) and 50 mu M cysteamine (Cyst)] or a pro-oxidant (5 mm buthionine sulfoximine) on the quality and penetrability of spermatozoa into bovine oocytes and on the subsequent embryo development and quality when added during IVF. Sperm quality, evaluated by the integrity of plasma and acrosomal membranes, and mitochondrial function, was diminished (p < 0.05) after 4-h culture in the presence of antioxidants. Oocyte penetration rates were similar between treatments (p > 0.05), but antioxidants adversely affected the normal pronuclear formation rates (p < 0.05). The incidence of polyspermy was high for beta-ME (p < 0.05). No differences were observed in cleavage rates between treatments (p > 0.05). However, the developmental rate to the blastocyst stage was adversely affected by Cyst treatment (p < 0.05). The quality of embryos that reached the blastocyst stage, evaluated by total, inner cell mass (ICM) and trophectoderm cell numbers and ICM/total cell ratio was unaffected (p > 0.05) by treatments. The results indicate that ROS play a role in the fertilizing capacity in bovine spermatozoa, as well as in the interaction between the spermatozoa and the oocytes. It can be concluded that supplementation with antioxidants during IVF procedures impairs sperm quality, normal pronuclear formation and embryo development to the blastocyst stage.

Use of high and low velocity cervical manipulative therapy procedures by Australian manipulative physiotherapists

The use of cervical manipulation presents concerns because of a risk of devastating side effects of trauma to the vertebral artery. Little is known about the frequency of use of cervical manipulation versus passive mobilisation by physiotherapists. A recent national, multi-centre randomised clinical trial of the physiotherapy management of cervicogenic headache provided an opportunity to gain an insight into practices of a sample of manipulative physiotherapists across Australia. The treatment records for the 100 subjects who received only manipulative therapy, or manipulative therapy with exercise as per the trial protocol, were audited. The results revealed that cervical manipulation was used in 20.2% of the 1090 treatments provided to these subjects but cervical joint mobilisation only was used in the vast majority of treatments (77.6%). Nevertheless, 42% of subjects were treated with cervical manipulation at some time. In most instances, manipulation was accompanied by passive mobilisation in the same treatment session. Patients were manipulated on one to six occasions and this occurred predominantly in the latter half of the 12-treatment program. Cervical manipulation was used less frequently in the group who also received exercise. The data suggest that the physiotherapists participating in this study used cervical manipulation selectively and relatively conservatively considering the high use of cervical mobilisation techniques. This may reflect their due regard to safety in the treatment of the cervical region.

Ar-40/-Ar-39 geochronology at the Instituto de Geociencias, USP: instrumentation, analytical procedures, and calibration

Laser heating Ar-40/Ar-39 geochronology provides high analytical precision and accuracy, mum-scale spatial resolution. and statistically significant data sets for the study of geological and planetary processes, A newly commissioned Ar-40/Ar-39 laboratory at CPGeo/USP, Sao Paulo, Brazil, equips the Brazilian scientific community with a new powerful tool applicable to the study of geological and cosmochemical processes. Detailed information about laboratory layout, environmental conditions, and instrumentation provides the necessary parameters for the evaluation of the CPGeo/USp Ar-40/Ar-39 suitability to a diverse range of applications. Details about analytical procedures, including mineral separation, irradiation at the IPEN/CNEN reactor at USP, and mass spectrometric analysis enable potential researchers to design the necessary sampling and sample preparation program suitable to the objectives of their study. Finally, the results of calibration tests using Ca and K salts and glasses, international mineral standards, and in-house mineral standards show that the accuracy and precision obtained at the Ar-40/Ar-39 laboratory at CPGeo/USP are comparable to results obtained in the most respected laboratories internationally. The extensive calibration and standardization procedures under-taken ensure that the results of analytical studies carried out in our laboratories will gain immediate international credibility, enabling Brazilian students and scientists to conduct forefront research in earth and planetary sciences.