Surface-enhanced Raman spectroscopy (SERS): a powerful technique to study the SEI layer in batteries.

The solid electrolyte interphase (SEI) layer on a silicon anode is investigated by SERS. Gold electrodeposition on a silicon electrode is confirmed by SEM, and Raman enhancement is proved, allowing determination of the partial composition of its SEI. For the first time, organophosphate-derivatives seem to be detected by Raman.

Capacity fade in high energy silicon-graphite electrodes for lithium-ion batteries.

A silicon-graphite blended anode is paired with a high capacity LiFePO4 reference/counter electrode to track irreversibility and lithium inventory. The LiFePO4 electrode provides a reliable, flat potential for dQ dV-1 analysis of LixSi and LixC electrochemical reactions. We relate this electrochemistry to the morphological and physical changes taking place.

Development of a Short Questionnaire to Assess Diet Quality among Older Community-Dwelling Adults.

OBJECTIVE: To evaluate the use of a short questionnaire to assess diet quality in older adults. DESIGN: Cross-sectional study. SETTING: Hertfordshire, UK. PARTICIPANTS: 3217 community-dwelling older adults (59-73 years). MEASUREMENTS: Diet was assessed using an administered food frequency questionnaire (FFQ); two measures of diet quality were defined by calculating participants' 'prudent diet' scores, firstly from a principal component analysis of the data from the full FFQ (129 items) and, secondly, from a short version of the FFQ (including 24 indicator foods). Scores calculated from the full and short FFQ were compared with nutrient intake and blood concentrations of vitamin C and lipids. RESULTS: Prudent diet scores calculated from the full FFQ and short FFQ were highly correlated (0.912 in men, 0.904 in women). The pattern of associations between nutrient intake (full FFQ) and diet scores calculated using the short and full FFQs were very similar, both for men and women. Prudent diet scores calculated from the full and short FFQs also showed comparable patterns of association with blood measurements: in men and women, both scores were positively associated with plasma vitamin C concentration and serum HDL; in women, an inverse association with serum triglycerides was also observed. CONCLUSIONS: A short food-based questionnaire provides useful information about the diet quality of older adults. This simple tool does not require nutrient analysis, and has the potential to be of value to non-specialist researchers.

Systematic review of self-expanding stents in the management of benign colorectal obstruction.

AIM: Colorectal obstruction due to benign disease is likely to become more prevalent. Self-expanding stents have been shown to be effective in reducing morbidity and allowing one-stage resection or improved palliation in colorectal cancer. This review assessed the use of self-expanding stents in benign colorectal obstruction. METHOD: A systematic review was performed using PubMed, Embase and the Cochrane Library. Keywords included: 'benign disease' 'colorectal obstruction', 'stent', 'endoprosthesis' and 'prosthesis' Original articles from all relevant listings were sourced. These were hand searched for further articles of relevance. The main outcome measures assessed were technical and clinical success, perforation, reobstruction and stoma avoidance in the bridge to surgery population. RESULTS: The search strategy identified 130 articles; the 21 included studies yielded a pooled analysis of 122 patients. Diverticulitis was the predominant aetiology (66/122, 54%). Technical success was achieved in 115/122 (94%) and clinical success in 108/120 (87%) patients. Overall, the perforation rate was 12% (15/122) and the reobstruction rate was 14% (17/122). A stoma was avoided in 48% (23/48) of bridge to surgery patients. Perforation and stoma avoidance in the bridge to surgery group were worse with an aetiology of diverticulitis. CONCLUSION: Complication rates in stenting for benign colorectal obstruction are higher than for malignant obstruction. On the basis of limited published evidence, stenting cannot be recommended for benign colorectal obstruction.

A regional survey of emergency surgery: the trainees' perspective.

The reduction of junior doctors' hours and the 'Calmanisation' of higher surgical trainees have led to an inevitable decrease in clinical experience. The development of subspecialisation within general surgery limits the diversity of elective operative experience, while the resident surgical registrar continues to be faced by the same range of emergencies. Procedures such as tracheostomy, thoracotomy and emergency burr hole, although rare in an emergency setting, are seldom seen by surgical trainees outside ENT, cardiothoracic and neurosurgical departments, respectively. However, these life saving procedures continue to be within the remit of the general surgeon, and were considered as essential knowledge in the operative viva of the FRCS examination.

Intravenous infusion cholangiography for investigation of the bile duct: a direct comparison with endoscopic retrograde cholangiopancreatography.

Laparoscopic cholecystectomy has led to an increase in preoperative endoscopic retrograde cholangiopancreatography (ERCP) for the investigation of bile duct stones. ERCP and intravenous infusion cholangiography (IIC) were compared in 111 consecutive patients without jaundice considered to be at high risk for bile duct stones. Both investigations were successfully completed in 100 patients. IIC and ERCP demonstrated a normal bile duct in 81 patients and bile duct stones in 16 patients. IIC failed to identify bile duct stones in two patients (1.8 per cent). IIC was 89 per cent sensitive and 99 per cent specific for detecting bile duct stones in patients without jaundice. It is suggested that IIC is a cost-effective preoperative investigation for bile duct calculi.

An experimental study of altered nitric oxide metabolism as a mechanism of cyclosporin-induced renal vasoconstriction.

Nephrotoxicity caused by cyclosporin A (CSA) is the result of vasoconstriction of the renal microcirculation. The endothelium-derived relaxing factor nitric oxide (NO) regulates microvascular blood flow in various tissues, and mediates the microcirculatory response during hypertension and sepsis. This study investigated the role of NO in CSA-induced renal vasoconstriction. Hydronephrotic kidneys in rats were suspended in an environmentally controlled tissue bath, and interlobular, afferent and efferent arteriolar diameters and blood flow were measured by in vivo videomicroscopy. CSA was administered alone, with the nitric oxide synthase (NOS) inhibitor N omega-nitro-L-arginine methyl ester (L-NAME) or with exogenous NOS substrate L-arginine. CSA significantly constricted the whole of the renal microvasculature whereas L-NAME alone preferentially constricted the preglomerular vessels. L-Arginine reversed the vasoconstriction induced by CSA whereas L-NAME had no further effect. Preglomerular basal vascular tone is dependent on continuous production of NO and alterations in the L-arginine-NO pathway contribute to CSA-induced renal vasoconstriction.

Renal microvascular responses to sepsis are dependent on nitric oxide.

Nitric oxide (NO) is an important mediator of the hemodynamic response to sepsis; however, its visceral microcirculatory effects are largely unknown. To determine the role of NO in renal microvascular responses to bacteremia, rat hydronephrotic kidneys with intact neurovascular supplies were exteriorized into a tissue bath. Videomicroscopy was used to measure vessel diameters (interlobular artery, ILA; afferent arteriole, AFF; efferent arteriole, EFF) and optical Doppler velocimetry was used to quantitate ILA flow. In controls, topical L-arginine (L-Arg; 10(-4) M), the NO synthase (NO-S) substrate, resulted in mild pre- and postglomerular dilation and increased flow. Inhibition of NO-S by N omega-nitro-L-arginine methyl ester (L-NAME: 10(-4) M) caused preglomerular constriction (ILA = -22%; AFF = -20% from baseline) and reduced ILA flow by 39%, while postglomerular diameters (EFF) were unchanged. Bacteremic rats had similar alterations (ILA = -22%; AFF = -20%; flow = -56%). Topical L-NAME in bacteremic rats resulted in further constriction (ILA = -38%; AFF = -37%), decreased ILA flow (-75%) and constricted EFF (-30%). L-Arg ameliorated constriction (ILA = -11%; AFF = -7%) and flow (-34%) during bacteremia. We conclude that: (1) NO is important in basal preglomerular tone; (2) Escherichia coli causes selective preglomerular constriction and hypoperfusion; (3) maintenance of EFF tone during bacteremia is NO dependent; and (4) different pre- and postglomerular NO mechanisms exist during basal and bacteremic states. These data indicate that NO is an important mediator of renal microvascular responses to sepsis.

Acute cyclosporine-induced renal vasoconstriction is mediated by endothelin-1.

BACKGROUND: Cyclosporine causes intrarenal vasoconstriction, which may account for its nephrotoxic side effects. Plasma levels of the vasoconstrictor peptide endothelin-1 are increased after cyclosporine administration, and endothelin-1 has been shown to cause renal vasoconstriction. In this study we used in vivo microscopy to investigate the role of endothelin-1 in cyclosporine-induced vasoconstriction. METHODS: Hydronephrotic kidneys in decerebrate rats were suspended in an environmentally controlled tissue bath with neurovascular supply intact. Interlobular, afferent, and efferent arteriolar diameters and flow were measured by videomicroscopy and Doppler velocimetry. Cyclosporine was added to the tissue bath, and measurements were repeated for 60 minutes. In study groups endogenous endothelin-1 was blocked by infusion of either specific endothelin antiserum or an endothelin-1 receptor antagonist. RESULTS: Cyclosporine caused constriction of the interlobular artery by 20% +/- 2% and a corresponding decrease in blood flow by 66% +/- 4%. The afferent and efferent arterioles constricted to a similar degree. This vasoconstriction was entirely prevented by infusion of either the endothelin antiserum or the receptor antagonist. The antagonist reagents alone had no effect on hemodynamic parameters or renal microvessel diameters. CONCLUSIONS: The acute renal vasoconstriction induced by cyclosporine is mediated by endothelin-1. Endogenous endothelin-1 has little role in maintaining basal vascular tone.

Factors affecting renal microvascular blood flow in rat hyperdynamic bacteremia.

To determine whether angiotensin II and alpha-adrenergic activity contribute to the mechanism of impaired renal microvascular blood flow during hyperdynamic live Escherichia coli (E. coli) bacteremia, we used in vivo video microscopy in the chronic unilateral hydronephrotic kidney of decerebrate male Sprague-Dawley rats. Intravenous infusion of E. coli caused arteriolar constriction to 83 +/- 4% of baseline (BL) in cortical radial arteries (CRA), 82 +/- 3% of BL in afferent (AFF) arterioles, and decreased flow to 54 +/- 9% of BL. Subsequent local inhibition of renal prostaglandin synthesis with mefenamate increased preglomerular arteriolar constriction to 55 +/- 6% of BL in CRA and 51 +/- 6% of BL in AFF arterioles and decreased renal microvascular blood flow to 26 +/- 8% of BL values in E. coli animals but had no effect on control animals. Subsequent local renal angiotensin II receptor blockade with saralasin acetate increased renal microvascular blood flow in E. coli animals to 64 +/- 9% of BL by dilating CRA to 78 +/- 5% of BL and AFF arterioles to 89 +/- 5% of BL. Phentolamine caused further dilation of CRA to 104 +/- 7% BL and AFF arterioles to 116 +/- 109% and increased flow to 99 +/- 8% of BL. Acetylcholine increased diameters further to 110 +/- 3% of BL in CRA and 136 +/- 12% of BL in AFF arterioles. These data indicate that in our chronic hydronephrotic kidney model during E. coli bacteremia, renal microvascular tone is due to increased angiotensin II and alpha-adrenergic activity and some other, as yet, undefined factor.

Escherichia coli bacteremia exacerbates cyclosporine-induced renal vasoconstriction.

The clinical observation that cyclosporine (CSA) nephrotoxicity is particularly severe in patients during and following bacterial infections has recently been made. Transplant recipients develop a marked deterioration of graft function following Escherichia coli bacteremia secondary to urinary tract infection. CSA causes intrarenal vasoconstriction which may account for its nephrotoxicity. We therefore undertook a study using the split hydronephrotic kidney model to investigate the direct in vivo effects of CSA and E. coli bacteremia on the renal microcirculation. Hydronephrotic kidneys in Sprague-Dawley rats were suspended in an environmentally controlled tissue bath. Interlobular arterial (ILA) and afferent (AFF) and efferent (EFF) arteriolar diameters were measured by in vivo videomicroscopy and red cell velocity by Doppler velocimetry. Topical administration of CSA to the kidney in the tissue bath caused a 23 +/- 1% constriction of the ILA and a 67 +/- 5% reduction in blood flow. AFF and EFF arterioles were also constricted by 21 +/- 3 and 16 +/- 2%, respectively. The intravenous infusion of live E. coli was also followed by decreases in ILA diameters and flow (38 +/- 4 and 68 +/- 4%) and AFF diameters (22 +/- 5%) while EFF diameters were unchanged. The infusion of E. coli following addition of CSA to the tissue bath resulted in a dramatically increased constriction of ILA (49 +/- 4%) and AFF (31 +/- 2%) vessels and almost abolished ILA flow (90 +/- 2%). We conclude that in this model, E. coli bacteremia exacerbates CSA-induced preglomerular vasoconstriction and suggests a scientific basis for the severe renal dysfunction noted in transplant recipients during bacterial infection.

In vivo effects of endothelin on the renal microcirculation.

Endothelin-1 (ET) is a recently discovered vasoconstrictor peptide which is released by renal vascular endothelial cells in response to a number of pathologic insults including ischemia, endotoxemia, bacteremia, and cyclosporine nephrotoxicity. Because microvascular vasoconstriction is an integral component of the acute renal dysfunction associated with these conditions, this study was undertaken to determine the in vivo effects of ET on the renal microcirculation. We used the split hydronephrotic kidney model in decerebrate Sprague-Dawley rats to study vessel diameter and red cell velocity responses to ET using intravital videomicroscopy and doppler velocimetry. Topical administration of increasing concentrations of ET caused a dose-dependent constriction of interlobular arteries which reached a maximum of 27 +/- 5% at an ET concentration of 10(-8) M. A corresponding decrease of 64 +/- 8% in interlobular arterial blood flow was observed. Afferent and efferent arteriole diameters were reduced by 39 +/- 2% and 27 +/- 5%, respectively. These vascular effects were completely prevented by the systemic preinfusion of anti-endothelin antiserum. Infusion of antiserum alone had no effect on systemic hemodynamics or renal microvascular variables, suggesting that ET has little or no role in maintaining basal vascular tone in the kidney. We conclude that ET is a potent in vivo constrictor of the renal microcirculation and may be involved in mediating pathologic vasoconstriction.

A study of the personal meaning of suicide in the context of Baechler's typology.

This study investigates suicide from the vantage point of the suicidal person by analyzing the personal meaning(s) of the act for the individual. Twenty-seven suicidal persons and survivors contributed to the research. Their individual recollections are studied and ordered within the framework of Jean Baechler's approach (as presented in his book Suicides). The study indicates that there is, in each case, an identifiable purpose or a pattern of purposes that can be categorized within a restricted and meaningful system, which may help the observer understand what human beings are doing when they want to end their lives.

Estrogen use and myocardial infarction risk: a case-control study.

A case-control study was conducted to examine the relationship of estrogen use to myocardial infarction in postmenopausal white women. After exclusion of proxy responses and of controls with discharge diagnoses of gynecologic or gallbladder diseases, there remained 39 matched sets (33 pairs and 6 triplets). The unadjusted relative odds ratio (RO) for past estrogen use was found to be 0.83. However, after simultaneous adjustment for cardiovascular diseases, smoking, education, and type of menopause, the net RO was 0.61. Type of menopause was found to interact with estrogen use, in that the protective effect was seen mainly in surgical menopause women, in whom the net RO for estrogen use was 0.37. Although none of the results reached statistical significance, they are consistent with recent results indicating a protective effect for estrogen therapy in regard to coronary heart disease, mainly among women undergoing surgical menopause.