The role of C2 in nanocrystalline diamond growth

This paper presents findings from a study of nanocrystalline diamond (NCD) growth in a microwave plasma chemical vapour deposition (CVD) reactor. NCD films were grown using Ar/H2/CH4 and He/H2/CH4 gas compositions. The resulting films were characterised using Raman spectroscopy, scanning electron microscopy and atomic force microscopy. Analysis revealed an estimated grain size of the order of 50 nm, growth rates in the range 0.01 to 0.3 um/h and sp3 and sp2 bonded carbon content consistent with that expected for NCD. The C2 Swan band was probed using cavity ring-down spectroscopy (CRDS) to measure the absolute C2 (a) number density in the plasma during diamond film growth. The number density in the Ar/H2/CH4 plasmas was in the range 2 to 4 x 10^12 cm-3, but found to be present in quantities too low to measure in the He/H2/CH4 plasmas. Optical emission spectrometry (OES) was employed to determine the relative densities of the C2 excited state (d) in the plasma. The fact that similar NCD material was grown whether using Ar or He as the carrier gas suggests that C2 does not play a major role in the growth of nanocrystalline diamond.Comment: 39 pages, 11 figure

Ocjena radne sposobnosti pacijenta s Wilsonovom bolesti - prikaz bolesnika

Wilson’s disease (WD) is a rare, progressive autosomal recessive disorder characterised by impaired transport and excessive accumulation of copper in the liver, brain, and other tissues. The disease is diagnosed based on clinical manifestations and screening tests results. Work ability assessment of patients with WD is based on the analysis of liver, kidney, neurological, and cognitive impairments, and takes into account patient’s level of education. This article presents a case with a 48-year-old male patient, who was admitted for work ability assessment due to polymorphic symptoms. The patient had been working as a salesman for 28 years. A detailed interview and examination by occupational health and other medical specialists revealed that the patient had been suffering from Wilson’s disease from the age of 13, and had now developed hepatic manifestations (compensated liver cirrhosis with portal hypertension), neurological manifestations (dystonia, dysarthria, muscle weakness, vertigo), and psychiatric manifestations (depression, insomnia, cognitive impairment) of the disease, including problems partially caused by long-lasting treatment with copper chelating agents (neurological and haematological manifestations). There were no ocular manifestations of Wilson’s disease (Kayser-Fleischer rings or sunflower cataract). The patient was assessed as having drastically diminished general work ability, dominantly due to neurological and psychiatric impairments caused by Wilson’s disease.Wilsonova je bolest rijetka, progresivna autosomno recesivna bolest karakterizirana poremećajem transporta bakra i posljedičnim prekomjernim nakupljanjem bakra u jetri, mozgu i drugim tkivima i organima. Dijagnoza bolesti postavlja se na osnovi kliničkih manifestacija bolesti i nalaza laboratorijskih ispitivanja. Ocjena radne sposobnosti pacijenata s Wilsonovom bolesti zasniva se na analizi postojanja oštećenja i stupnja oštećenja hepatičkih, neuroloških, bubrežnih i kognitivnih funkcija, kao i na analizi stupnja obrazovanja pacijenata. Prikazan je slučaj D. M., 48-godišnjeg pacijenta, koji je primljen zbog polimorfnih tegoba na bolničko ispitivanje radi ocjene radne sposobnosti. Pacijent je radio kao prodavač posljednjih 28 godina. Nakon detaljne anamneze i pregleda koje su obavili specijalisti medicine rada i drugi specijalisti utvrđeno je da pacijent boluje od Wilsonove bolesti od 13. godine života i da u ovom trenutku ima izražene hepatične manifestacije (kompenzirana ciroza jetre s portalnom hipertenzijom), neurološke manifestacije (distonija, dizartrija, mišićna slabost, vrtoglavica) i psihijatrijske manifestacije (depresija, nesanica, kognitivno oštećenje) Wilsonove bolesti, kao i da su prisutne tegobe djelomično uzrokovane dugotrajnom upotrebom kelatne terapije (neurološki i hematološki poremećaji). Nisu uočene karakteristične očne promjene Wilsonove bolesti (Kayser-Fleischerov prsten, katarakta u obliku suncokreta). Ocjenom radne sposobnosti utvrđeno je da pacijent ima drastično smanjenu radnu sposobnost pretežno zbog neuroloških i psihičkih poremećaja u sklopu Wilsonove bolesti

Diabetes Risk Perception and Intention to Adopt Healthy Lifest yles Among Primary Care Patients

OBJECTIVE—To examine perceived risk of developing diabetes in primary care patients. RESEARCH DESIGN AND METHODS—We recruited 150 nondiabetic primary care patients. We made standard clinical measurements, collected fasting blood samples, and used the validated Risk Perception Survey for Developing Diabetes questionnaire. RESULTS—Patients with high perceived risk were more likely than those with low perceived risk to have a family history of diabetes (68 vs. 18%; P < 0.0001) and to have metabolic syndrome (53 vs. 35%; P = 0.04). However, patients with high perceived risk were not more likely to have intentions to adopt healthier lifestyle in the coming year (high 26.0% vs. low 29.2%; P = 0.69). CONCLUSIONS—Primary care patients with higher perceived risk of diabetes were at higher actual risk but did not express greater intention to adopt healthier lifestyles. Aspects of health behavior theory other than perceived risk need to be explored to help target efforts in the primary prevention of diabetes

XRCC1 haploinsufficiency in mice has little effect on aging, but adversely modifies exposure-dependent susceptibility

Oxidative DNA damage plays a role in disease development and the aging process. A prominent participant in orchestrating the repair of oxidative DNA damage, particularly single-strand breaks, is the scaffold protein XRCC1. A series of chronological and biological aging parameters in XRCC1 heterozygous (HZ) mice were examined. HZ and wild-type (WT) C57BL/6 mice exhibit a similar median lifespan of ~26 months and a nearly identical maximal life expectancy of ~37 months. However, a number of HZ animals (7 of 92) showed a propensity for abdominal organ rupture, which may stem from developmental abnormalities given the prominent role of XRCC1 in endoderm and mesoderm formation. For other end-points evaluated—weight, fat composition, blood chemistries, condition of major organs, tissues and relevant cell types, behavior, brain volume and function, and chromosome and telomere integrity—HZ mice exhibited by-and-large a normal phenotype. Treatment of animals with the alkylating agent azoxymethane resulted in both liver toxicity and an increased incidence of precancerous lesions in the colon of HZ mice. Our study indicates that XRCC1 haploinsufficiency in mammals has little effect on chronological longevity and many key biological markers of aging in the absence of environmental challenges, but may adversely affect normal animal development or increase disease susceptibility to a relevant genotoxic exposure

XRCC1 haploinsufficiency in mice has little effect on aging, but adversely modifies exposure-dependent susceptibility

Oxidative DNA damage plays a role in disease development and the aging process. A prominent participant in orchestrating the repair of oxidative DNA damage, particularly single-strand breaks, is the scaffold protein XRCC1. A series of chronological and biological aging parameters in XRCC1 heterozygous (HZ) mice were examined. HZ and wild-type (WT) C57BL/6 mice exhibit a similar median lifespan of ~26 months and a nearly identical maximal life expectancy of ~37 months. However, a number of HZ animals (7 of 92) showed a propensity for abdominal organ rupture, which may stem from developmental abnormalities given the prominent role of XRCC1 in endoderm and mesoderm formation. For other end-points evaluated—weight, fat composition, blood chemistries, condition of major organs, tissues and relevant cell types, behavior, brain volume and function, and chromosome and telomere integrity—HZ mice exhibited by-and-large a normal phenotype. Treatment of animals with the alkylating agent azoxymethane resulted in both liver toxicity and an increased incidence of precancerous lesions in the colon of HZ mice. Our study indicates that XRCC1 haploinsufficiency in mammals has little effect on chronological longevity and many key biological markers of aging in the absence of environmental challenges, but may adversely affect normal animal development or increase disease susceptibility to a relevant genotoxic exposure

Psychomotor control in a virtual laparoscopic surgery training environment: gaze control parameters differentiate novices from experts

Background: Surgical simulation is increasingly used to facilitate the adoption of technical skills during surgical training. This study sought to determine if gaze control parameters could differentiate between the visual control of experienced and novice operators performing an eye-hand coordination task on a virtual reality laparoscopic surgical simulator (LAP Mentor™). Typically adopted hand movement metrics reflect only one half of the eye-hand coordination relationship; therefore, little is known about how hand movements are guided and controlled by vision. Methods: A total of 14 right-handed surgeons were categorised as being either experienced (having led more than 70 laparoscopic procedures) or novice (having performed fewer than 10 procedures) operators. The eight experienced and six novice surgeons completed the eye-hand coordination task from the LAP Mentor basic skills package while wearing a gaze registration system. A variety of performance, movement, and gaze parameters were recorded and compared between groups. Results: The experienced surgeons completed the task significantly more quickly than the novices, but only the economy of movement of the left tool differentiated skill level from the LAP Mentor parameters. Gaze analyses revealed that experienced surgeons spent significantly more time fixating the target locations than novices, who split their time between focusing on the targets and tracking the tools. Conclusion: The findings of the study provide support for the utility of assessing strategic gaze behaviour to better understand the way in which surgeons utilise visual information to plan and control tool movements in a virtual reality laparoscopic environment. It is hoped that by better understanding the limitations of the psychomotor system, effective gaze training programs may be developed. © 2010 The Author(s).published_or_final_versionSpringer Open Choice, 01 Dec 201

Perceptual impairment and psychomotor control in virtual laparoscopic surgery

Background: It is recognised that one of the major difficulties in performing laparoscopic surgery is the translation of two-dimensional video image information to a three-dimensional working area. However, research has tended to ignore the gaze and eye-hand coordination strategies employed by laparoscopic surgeons as they attempt to overcome these perceptual constraints. This study sought to examine if measures related to tool movements, gaze strategy, and eye-hand coordination (the quiet eye) differentiate between experienced and novice operators performing a two-handed manoeuvres task on a virtual reality laparoscopic surgical simulator (LAP Mentor™). Methods: Twenty-five right-handed surgeons were categorised as being either experienced (having led more than 60 laparoscopic procedures) or novice (having performed fewer than 10 procedures) operators. The 10 experienced and 15 novice surgeons completed the "two-hand manoeuvres" task from the LAP Mentor basic skills learning environment while wearing a gaze registration system. Performance, movement, gaze, and eye-hand coordination parameters were recorded and compared between groups. Results: The experienced surgeons completed the task significantly more quickly than the novices, used significantly fewer movements, and displayed shorter tool paths. Gaze analyses revealed that experienced surgeons spent significantly more time fixating the target locations than novices, who split their time between focusing on the targets and tracking the tools. A more detailed analysis of a difficult subcomponent of the task revealed that experienced operators used a significantly longer aiming fixation (the quiet eye period) to guide precision grasping movements and hence needed fewer grasp attempts. Conclusion: The findings of the study provide further support for the utility of examining strategic gaze behaviour and eye-hand coordination measures to help further our understanding of how experienced surgeons attempt to overcome the perceptual difficulties inherent in the laparoscopic environment. © 2011 The Author(s).published_or_final_versionSpringer Open Choice, 21 Feb 201