Lithium silicon sulfide as an anode material in all-solid-state lithium batteries

The electrochemical properties of Li₂SiS₃ were investigated in a solid electrolyte. Li₂SiS₃ was converted to elemental Si, and the resultant Si was formed into Si-Li alloy in the reduction process; however, the reverse reaction was not completed due to the loss of electronic conduction upon reoxidation. FeS was dispersed as a conductive additive in Li₂SiS₃ films by pulsed laser deposition (PLD). The addition allowed successive reactions to proceed at a large capacity with small capacity-fading during the cycling process in spite of the small FeS fraction. This result indicates that Li₂SiS₃ + FeS thin film is a promising anode for solid-state lithium batteries.     

Developing a culture of lifelong learning in a library environment

Between 1995 and 1996, the Annette and Irwin Eskind Biomedical Library (EBL) at Vanderbilt University Medical Center (VUMC) radically revised the model of service it provides to the VUMC community. An in-depth training program was developed for librarians, who began to migrate to clinical settings and establish clinical librarianship and information brokerage services beyond the library's walls. To ensure that excellent service would continue within the library, EBL's training program was adapted for library assistants, providing them with access to information about a wide variety of work roles and processes over a four to eight-month training period. Concurrently, customer service areas were reorganized so that any question--whether reference or circulation--could be answered at any of four service points, eliminating the practice of passing customers from person to person between the reference and circulation desks. To provide an incentive for highly trained library assistants to remain at EBL, management and library assistants worked together to redesign the career pathway based on defined stages of achievement, self-directed participation in library-wide projects, and demonstrated commitment to lifelong learning. Education and training were the fundamental principles at the center of all this activity.     

Histamine immunoreactive axons in the macaque retina

PURPOSE: The goal of these experiments was to identify the neurotransmitter in centrifugal axons of the macaque retina. METHODS: Macaca mulatta retinas and optic nerves were fixed overnight in carbodiimide and labeled with an antiserum to histamine with the use of an immunofluorescence technique. RESULTS: Several large histamine-immunoreactive axons ran from the optic nerve head to the peripheral retina, where they branched extensively and terminated in the inner plexiform layer, occasionally alongside retinal blood vessels. Other axons that emerged from the optic nerve head ran in the optic fiber layer to the central retina, circled the fovea, and then returned to the optic disc. These may be the source of histamine-immunoreactive axons that have been observed in central visual areas. No labeled cell bodies were present in the retina. Because perikarya in the posterior hypothalamus are the only known source of histamine in the primate central nervous system and because neurons there can be retrogradely labeled from the cut optic nerve, the histamine-immunoreactive axons must have originated there. CONCLUSIONS: Centrifugal axons in the macaque retina are part of the system of axons containing histamine that originate in the hypothalamus and project throughout the brain. Because the activity of these neurons is highest during the morning, histamine might play a role in preparing the retina to operate in daylight. The contacts of histamine-immunoreactive axons with blood vessels suggest that histamine may also play a role in regulating the retinal microvasculature.     

Optimal control of an aluminum casting furnace: Part I. The control model

This is a series of two articles on the control of an aluminum casting furnace to bring a mass of liquid aluminum from a known initial temperature to a desired final temperature in a given time with minimal fuel cost. An analytic model of the furnace already exists but is too complex for control purposes. Here in Part I, a simplified nonlinear control model is derived from the analytic model. In Part II, an optimization of the fuel flow is performed on the control model using Pontryagin’s maximum principle. The first article shows that despite the complexity of the analytic model, a tenth-order nonlinear control model with good representativity can be obtained. The second article shows that the maximum principle applied to this problem leads to a solution with optimal fuel cost. If modeling industrial processes is a complex problem in itself, obtaining a control model therefrom is just as delicate. This series of articles proposes an approach that works for the casting furnace and is indeed applicable to other industrial processes as well. In the existing analytic model, the casting furnace is treated as two one-dimensional conducting media (metal and refractories), while its chamber is seen as a well-stirred reactor. In this article, a control model is derived therefrom by a statistical method. The analytic model is run several times to obtain a set of predicted data on which a least-squares approximation is performed to determine the best parameter values to be used for the control model equations. The conduction equations in the two media are linear. The expressions for heat generation in the chamber and for radiative-convective heat transfer from the chamber to the two media are nonlinear and are kept to ensure maximum representativity. The result is a highly representative tenth-order control model, the degree of representativity being assessed by comparing the temperature outputs and the energy balances obtained from the analytic model with those obtained from the control model.     

Genomic variation of human papillomavirus type 16 and risk for high grade cervical intraepithelial neoplasia

BACKGROUND: Epidemiologic studies have demonstrated strong and consistent associations between the detection of human papillomavirus (HPV) type 16 DNA and the risk of cervical intraepithelial neoplasia (CIN) and cervical cancer. However, HPV16 is also the most common type of HPV in the normal population, and only a minority of women with HPV16 infection develop cervical cancer. Studies of genomic heterogeneity in HPV16 have demonstrated the presence of multiple variant forms in all human populations examined to date. It is conceivable that the natural variants of HPV16 in a given population may not have the same biologic behavior. PURPOSE: This study was designed to determine the association between natural variants of HPV16 and the risk of biopsy-confirmed CIN 2 or 3, the most important precancerous lesions of the uterine cervix. METHODS: Prospective studies were conducted among 1) women attending a university and 2) women presenting to a sexually transmitted disease clinic. Subjects were eligible for inclusion in this investigation if the initial cytologic findings did not reveal CIN 2-3 and HPV16 DNA was detected by means of a polymerase chain reaction (PCR)-based method in one or more cervical or vulvovaginal samples. Eligible subjects were followed every 4 months with cervical Pap smears and colposcopic examinations. Women were referred for biopsy if cytology or colposcopy suggested CIN 2-3. Two groups of HPV16 variants, prototype-like and nonprototype-like, were determined by means of single-strand conformation polymorphism (SSCP) analysis of PCR products from the noncoding region of the viral genome. Representative SSCP patterns from HPV16 variants were further characterized by direct DNA sequencing of the PCR products. Relative risks (RRs) and 95% confidence intervals (CIs) were calculated by Cox regression analysis. RESULTS: Prototype-like variants accounted for 79% of the HPV16 detected in university students and 86% of the virus detected in patients presenting to the sexually transmitted disease clinic. CIN 2-3 was confirmed by biopsy in nine of 57 HPV16-positive women attending the university and in 10 of 66 HPV16-positive women presenting to the sexually transmitted disease clinic. Among university students, those with HPV16 nonprototype-like variants were 6.5 (95% CI = 1.6-27.2) times more likely to develop CIN 2-3 than those with prototype-like variants. A similar association was observed among women presenting to the sexually transmitted disease clinic (RR = 4.5; 95% CI = 0.9-23.8). CONCLUSIONS: This study suggests that the risk of developing CIN 2-3 is not the same with all variants of HPV16 and that nonprototype-like variants confer a greater risk compared with prototype-like variants. The important genomic differences underlying this increased risk of CIN 2-3 remain to be determined.     

Ornithine decarboxylase activity in muscle, liver, and intestinal tissue of turkeys during a short-term feed withdrawal and following refeeding

The activity of ornithine decarboxylase (ODC), an enzyme associated with cellular growth and protein synthesis, was examined in breast muscle, liver, and intestinal tissues of turkeys during a short-term period of feed withdrawal (FW) and following refeeding. Turkeys from a randombred control line were reared under standard management practices to 3 wk of age in battery brooders. Feed was then withdrawn from FW birds for a 48-h period, after which feed was consumed ad libitum. Control birds consumed feed ad libitum throughout the test period. Tissues were collected from 12 birds per treatment following 24 and 48 h of FW and at 6, 12, 24, and 48 h following refeeding for later determination of tissue ODC activity. Activity of ODC was greater in tissue from the small intestine than in liver tissue and both had greater activity than that exhibited by breast muscle. Short-term FW and refeeding produced differential responses in ODC activity of the three tissues examined. Feed withdrawal resulted in a reduction of ODC activity in intestinal tissue, whereas activity was unaffected for liver or breast muscle tissues. Compensatory increases in ODC activity were observed in liver and intestinal tissues; however, the increase was both more rapid and transitory in small intestine than in liver tissue. The ODC activity in breast muscle was largely unaffected by short-term FW and refeeding. Patterns of ODC activity in liver during FW and refeeding closely resembled patterns observed for absolute and relative liver weight. Thus, the results of the present experiment demonstrate that short-term FW and refeeding influence underlying growth mechanisms of supply organs, such as hepatic and intestinal tissue, in addition to affecting overall growth and muscle development.     

Radiofrequency volumetric tissue reduction for treatment of turbinate hypertrophy: a pilot study

BACKGROUND: Apoptosis maintains cell homeostasis. Altered apoptosis is involved in carcinogenesis. It was our aim to investigate whether reflux esophagitis may alter apoptosis in the esophageal mucosa and whether antireflux surgery may restore normal apoptosis. METHODS: Apoptosis was studied preoperatively and postoperatively in esophageal biopsies of 39 patients with various grades of reflux esophagitis and in Barrett's mucosa using the TUNEL method. Biopsies were also taken from lesions of the squamous epithelium adjacent to the Barrett's mucosa. RESULTS: Apoptosis increased with the severity of esophagitis. Apoptosis was low in Barrett's epithelium. Squamous epithelium adjacent to Barrett's mucosa showed increased apoptosis. After surgery apoptosis decreased in squamous epithelium, and it remained low in Barrett's epithelium. CONCLUSIONS: Apoptosis in reflux esophagitis may be protective against increased proliferation. Low apoptosis following antireflux surgery indicates that surgery is effective to prevent reflux-induced cell proliferation. Inhibition of apoptosis in Barrett's may promote carcinogenesis. This may not change following surgery.     

Effect of metal-sulfide additives on electrochemical properties of nano-sized Fe2O3-loaded carbon for Fe/air battery anodes

In the present study, K₂S and Bi₂S₃ were used as additives in electrolytes and electrodes, respectively. The effects of these additives on the electrochemical properties of nano-sized Fe₂O₃-loaded carbon electrodes were investigated using cyclic voltammetry (CV), galvanostatic cycling performance and scanning electron microscopy (SEM), along with electron dispersive spectroscopy (EDS). The results showed that both K₂S and Bi₂S₃ significantly reduced hydrogen evolution and benefited the Fe₂O₃-loaded carbon electrode, such as by retarding passivation and improving the discharge capacity. The effects of metal sulfide additives depended on the carbon used. For Bi₂S₃ additive, all carbons provided larger capacities than acetylene black (AB) while AB gave greater capacity than other carbons when K₂S was used.