bluuebunny/crossref_metadata_2025 huggingface dataset:
Distinct Inhibitory Neurons Exert Temporally Specific Control over Activity of a Motoneuron ReceivingConcurrent Excitation and Inhibition
Authors: Sasaki Kosei , Brezina Vladimir , Weiss Klaudiusz R. , Jing Jian
Published: September 2009

Recent work suggests that concurrent excitation and inhibition originating in central pattern generators (CPGs) may be used to control rhythmic motoneuronal activity. The specific roles that the inhibition plays in such cases are not well understood, however, in part because of the lack of identification of presynaptic inhibitory neurons. Here we demonstrate that, in theAplysiafeeding CPG, inhibitory inputs may be critical for flexible control of the activity of motoneurons in different forms of behavior. The feeding CPG generates ingestive and egestive motor programs, differing in the high and low activity, respectively, of the motoneuron B8 during the retraction phase of the programs. We show that, during retraction, B8 receives concurrent excitation and inhibition that produces a high-conductance state. The inhibition originates in two types of CPG neurons, B4/5 and B70, that are more active in egestion than ingestion and play a role in suppressing B8 activity during egestion. In turn, the activities of both B4/5 and B70 are suppressed by the ingestion-promoting descending interneuron CBI-3 (for cerebral–buccal interneuron 3). Thus, concurrent excitation and inhibition may be an effective means of controlling motoneuronal activity in a behavior-dependent manner. More detailed analyses reveal, furthermore, that B4/5 and B70 exert complementary actions by acting preferentially in the early and late part of retraction, respectively. Thus, the use of multiple neurons to generate inhibitory inputs to motoneurons that receive concurrent excitation and inhibition brings an additional level of flexibility that allows a temporally specific control of motoneuronal activity within a single phase of motor programs.
Drehstromaggregate prüfen ohne WicklungstrennungTest of Three-Phase Aggregates without Coil Separation
Authors: Bähnck Frauke , Wagner Friedrich Ernst
Published: September 2009

Während bisher die Prüfung der einzelnen Wicklungen von Drehstromaggregaten auf Windungsschluss nur durch Öffnen des Aggregats und Eingriff in die Verdrahtung möglich ist, erlaubt das hier beschriebene Verfahren, die Wicklungswiderstände eines Drehstromaggregats, die Induktivitäten der einzelnen Wicklungen und Verpolungen in den Wicklungssträngen zu bestimmen, ohne die Schaltung auftrennen zu müssen. Zur Durchführung des Verfahrens wurde von den Autoren eine Schaltung und eine Software entwickelt, mit deren Hilfe die Messwerte erfasst und verarbeitet werden, unabhängig davon, ob die Wicklungen im Stern oder im Dreieck liegen und ohne Zugriff auf den Mittelpunkt der Sternschaltung. Die Einführung dieses computergeführten Prüfverfahrens in der Qualitätssicherung von Drehstromaggregaten sorgt für eine neue zerstörungsfreie, zeit- und kosteneffiziente Prüfmöglichkeit.
Synthesis and crystallographic structure of boron derivatives of N-(2-hydroxy-naphthylmethyl)-L-proline
Authors: Gawdzik Barbara , Iwanek Waldemar , Hoser Anna , Wozniak Krzysztof
Published: September 2009

A highly diastereoselective synthesis (>98%) of novel chiral (3aS)-4-oxo-6-phenyl-2,3,3a,4,6,14-hexahydro-1H-naphtho[1,2-e]pyrrolo[1′,2′:3,4][1,3,2]oxazaborolo-[2,3-b][1,3,2]oxazaborinin-15-ium-6-uide (2a) and (3aS)-6-(naphthalen-2-yl)-4-oxo-2,3,3a,4,6,14-hexahydro-1H-naphtho[1,2-e]pyrrolo[1′,2′:3,4][1,3,2]oxazaborolo[2,3-b][1,3,2] oxazaborinin-15-ium-6-uide (2b) compounds is described and details of the crystal structures are presented.
The effect of body mass index on the diagnosis of GH deficiency in patients at risk due to a pituitary insult
Authors: Tzanela Marinella , Zianni Dimitra , Bilariki Kalliopi , Vezalis Alexandros , Gavalas Nikos , Szabo Andrea , Drimala Panagiota , Vassiliadi Dimitra , Vassilopoulos Charalambos
Published: September 2009

Objectives

Diminished GH response to stimulation has been demonstrated in obesity, leading to erroneous diagnosis of GH deficiency. The aim of this study was to evaluate the influence of body mass index (BMI) on GH responsiveness in patients at risk for pituitary function deficits.

Methods

A total of 59 healthy subjects and 75 patients with a pituitary insult underwent insulin tolerance test or pyridostigmine+GHRH test in order to assess GH secretory reserve. Normal subjects and patients were classified as normal weight (BMI <24.9 kg/m2), overweight (BMI 25–29.9 kg/m2), and obese (BMI >30 kg/m2).

Results

All normal individuals with BMI <24.9 kg/m2 demonstrated adequate GH responses, while three of the 21 overweight (14.3%) and nine of the 28 obese subjects (32.1%) did not respond to GH stimulation. Among patients, four of 14 (28.6%) with BMI <24.9 kg/m2, 18 of 22 (81.8%) who were overweight, and 28 of 39 (71.7%) who were obese did not respond to GH stimulation. Of the 46 nonresponder patients with increased BMI, nine (19.6%) had normal insulin-like growth factor 1 (IGF1) values and no other pituitary hormone deficits, raising questions about the accuracy of somatotroph function assessment, while all nonresponders with BMI <24.9 kg/m2 had low IGF1 values and panhypopituitarism.

Conclusions

Our results indicate that BMI >25 kg/m2 has a negative effect on GH response not only in normal healthy subjects but also in patients at risk for pituitary function deficit as well. Parameters such as IGF1 levels and anterior pituitary deficits should be taken into account to accurately assess GH status in these patients.
Gamma knife radiosurgery: a safe and effective salvage treatment for pituitary tumours not controlled despite conventional radiotherapy
Authors: Swords F M , Monson J P , Besser G M , Chew S L , Drake W M , Grossman A B , Plowman P N
Published: September 2009

Objective

We report the use of ‘gamma knife’ (GK) radiosurgery in 25 patients with pituitary adenomas not cured despite conventional therapy, including external beam radiotherapy.

Patients and methods

All patients had previously received conventional radiotherapy for a mean of 11.8 years prior to receiving GK; 23 out of 25 had also undergone pituitary surgery on at least one occasion. Seventeen had hyperfunctioning adenomas that still required medical therapy without an adequate biochemical control – ten somatotroph adenomas, six corticotroph adenomas and one prolactinoma, while eight patients had non-functioning pituitary adenomas (NFPAs).

Results

Following GK, mean GH fell by 49% at 1 year in patients with somatotroph tumours. Serum IGF1 fell by 32% at 1 year and by 38% at 2 years. To date, 80% of the patients with acromegaly have achieved normalisation of IGF1, and 30% have also achieved a mean GH level of <1.8 ng/ml correlating with normalised mortality. A total of 75% NFPAs showed disease stabilisation or shrinkage post GK. The patient with a prolactinoma showed a dramatic response: 75% reduction in prolactin at 2 years, with a marked shrinkage on magnetic resonance imaging. The results in corticotroph adenomas were variable. Prior to GK, 72% of the patients were panhypopituitary, and 42% of the remainder have developed new anterior pituitary hormone deficiencies to date. No other adverse events have been detected at a mean follow-up of 36.4 months.

Conclusions

These data indicate that GK is a safe and effective adjunctive treatment for patients with NFPAs and acromegaly not satisfactorily controlled with surgery and radiotherapy.
Free leptin index and thyroid function in male highly trained athletes
Authors: Perseghin Gianluca , Lattuada Guido , Ragogna Francesca , Alberti Giampietro , La Torre Antonio , Luzi Livio
Published: September 2009

Objective

Exercise training may cause changes in thyroid function. This thyroid response may be due to exercise-induced modulation of energy metabolism but also of the adipocytes endocrine function. In particular, the role of leptin and of circulating soluble leptin receptor (sOB-R) was unexplored. The aim of this study was to assess the relationships between thyroid function, whole body energy metabolism, and adipokines – mainly leptin and its receptor, sOB-R.

Methods

We measured serum TSH, free tri-iodothyronine (FT3), free thyroxine, leptin, and sOB-R and assessed energy homeostasis by means of indirect calorimetry, in 27 highly trained athletes and 27 sedentary, healthy men.

Results

TSH–FT3 ratio was lower in athletes (P<0.03), either in sustained power or anaerobic power-sprint athletes (n=13) or marathon runners (n=14). Whole body respiratory quotient was lower in athletes. Fasting serum sOB-R was higher and leptin lower in athletes than controls. Also serum adiponectin, resistin, and retinol binding protein-4 concentrations were different in athletes than in controls. The ratio between leptin and sOB-R, the free leptin index (FLI), was lower in athletes than in controls (0.025±0.014 vs 0.085±0.049; P<0.001). In multivariate analysis, FLI retained independent association with TSH–FT3 ratio.

Conclusion

Male, elite athletes had lower TSH–FT3 ratio and FLI than controls while FLI was independently associated with TSH–FT3 ratio supporting the hypothesis that the level of biologically active leptin is involved in the adaptive response of thyroid function in professional athletes.
Narrow intra-individual variation of maternal thyroid function in pregnancy based on a longitudinal study on 132 women
Authors: Boas Malene , Forman Julie Lyng , Juul Anders , Feldt-Rasmussen Ulla , Skakkebæk Niels Erik , Hilsted Linda , Chellakooty Marla , Larsen Torben , Larsen Jørgen Falck , Petersen Jørgen H , Main Katharina M
Published: September 2009

Background

Adaptive alterations in maternal physiology cause changes in thyroid hormone levels throughout pregnancy, and precise biochemical evaluation is thus highly dependent on gestation-specific reference intervals and expected intra-individual variation.

Objective

The aim of the study was the assessment of the intra-individual variation as well as the longitudinal course of thyroid hormones during normal pregnancy and factors that influence the normal reference range for thyroid function. For this purpose, a longitudinal statistical model was applied.

Design

In a cohort of 132 pregnant women, serial blood samples were obtained and ultrasound scans were performed throughout pregnancy.

Methods

Serum levels of TSH, free and total thyroxine (T4), free and total triiodothyronine (T3) as well as autoantibodies against thyroid peroxidase and thyroglobulin were measured in 979 serum samples.

Results

Intra-individual variations of thyroid hormone concentrations were smaller than inter-individual variations (individuality index range: 0.38–0.71). Maternal height was positively associated with free T4 (FT4) (b=0.003; P=0.031) and pre-pregnancy body mass index with T3 and free T3 (b=0.017; <0.001 and b=0.007; P<0.001). Smoking was positively associated with T4 and FT4, but it was modulated by gestational age. Gestation-specific reference intervals for thyroid function variables from autoantibody-negative participants are presented.

Conclusions

In accordance with the data from nonpregnant adults, intra-individual variations of thyroid hormones were smaller than inter-individual variations also during pregnancy. In the evaluation of thyroid function in pregnancy, the individual longitudinal course of thyroid hormones rather than absolute values should be considered. We present a longitudinal model for the prediction of maternal thyroid function tests in pregnant women.
The investigation of applicability of the Hollomon-Jaffe equation on tempering the HSLA steel
Authors: Janjusevic Zoran , Gulisija Zvonko , Mihailovic Marija , Pataric Aleksandra
Published: September 2009

High strength low-alloyed (HSLA) Cr-Mn-Si steels belong to a group of steels that can reach their full mechanical properties after quenching and tempering. Those properties depend both on the temperature and time of tempering. Knowing the tempering parameters, it is possible to reach the desired properties of the treated steel. Some results on investigating the Hollomon-Jaffe equation (in parametric form) application for tempering of HSLA steel, are shown in this paper. The experiments were performed in real production conditions, using a standard material. The quenching was performed at 870?C, the heating period was always 30 min, with subsequent cooling into the oil bath. The tempering was carried out in temperature range from 480 to 680?C, while tempering time varied from 15 min to 24 h. The degree of tempering is referred through the hardness values changing. The experimental results have shown a pretty well agreement to tempering parameters, included in Hollomon-Jaffe equation, for this kind of HSLA steel.
Damage detection of hybrid aramid/metal-PVB composite materials using optical fiber sensors
Authors: Kojovic Aleksandar , Zivkovic Irena
Published: September 2009

Embedding optical fiber sensors within laminar thermoplastic composite material results in forming a system known as 'smart structure'. These sensors present the information about the inner structure health during the material exploitation and especially in the case of exterior impacts when a geometric configuration or the property changes of the material should be expected. This paper evaluates the feasibility of the real-time monitoring of indentation and low energy impact damage in composite laminates from indentation loading and Charpy pendulum impact, using the embedded intensity-based optical fiber sensors. An optical fiber sensing system, which relies solely on monitoring light intensity for providing the indication of the composite structural health, offers simplicity in design and cost-effectiveness. For this, aramid/polyvinylbutyral (PVB) and aramid/metal/PVB laminates with embedded optical fibers were fabricated. Four configurations of woven composites were tested, namely, aramid/PVB, and aramid/metal/PVB in three stacking sequences of aramid and metallic woven layers. The initiation of damage and fracture during testing was detected by observation of the intensity drop of light signal transmitted through an optical fiber.
Permanganometric determination of etamsylate in bulk drug and in tablets
Authors: Vinay K.B. , Revanasiddappa H.D. , Okram Zenita , Basavaiah Kanakapura
Published: September 2009

One titrimetric and two spectrophotometric methods which are simple, selective, sensitive, accurate, precise and economical for the determination of etamsylate (ETM) in bulk drug and in tablets employing permanganate as the oxidimetric reagent are described. In titrimetry, ETM is titrated directly with permanganate in sulphuric acid medium. A direct spectrophotometry (method A) involves treating the aqueous solution of the drug with permanganate in alkaline medium and measuring the bluish green product at 610 nm. In indirect spectrophotometry (method B), the drug solution was treated with a fixed concentration of permanganate in H2SO4 medium, and after a specified time, the unreacted permanganate was measured at 545 nm. The molar combining ratio in titrimetry and the optimum assay conditions were studied. Titrimetry is applicable over 1-10 mg range and the calculations are based on a 1:4 (ETM:KMnO4) molar ratio. In spectrophotometry, Beer's law is obeyed over 0.5- 5.0 and 1.5-15 ?g ml-1 for method A and B, respectively. The molar absorptivity values are calculated to be 2.79?104 and 4.17?104 l mol-1 cm-1 for method A and B, respectively and the corresponding sandell sensitivity values are 0.0094 and 0.0063 ?g cm-2. The limits of detection (LOD) and quantification (LOQ) are also reported for spectrophotometric methods. The applicability of the developed methods was demonstrated by the determination of etamsylate in pure drug as well as in commercial dosage forms.
The role of the thiol group in protein modification with methylglyoxal
Authors: Acimovic Jelena , Stanimirovic Bojana , Mandic Ljuba
Published: September 2009

Methylglyoxal is a highly reactive ?-oxoaldehyde with elevated production in hyperglycemia. It reacts with nucleophilic Lys and Arg side-chains and N-terminal amino groups causing protein modification. In the present study, the importance of the reaction of the Cys thiol group with methylglyoxal in protein modification, the competitiveness of this reaction with those of amino and guanidine groups, the time course of these reactions and their role and contribution to protein cross-linking were investigated. Human and bovine serum albumins were used as model systems. It was found that despite the very low levels of thiol groups on the surface of the examined protein molecules (approx. 80 times lower than those of amino and guanidino groups), a very high percentage of it reacts (25-85 %). The amount of reacted thiol groups and the rate of the reaction, the time for the reaction to reach equilibrium, the formation of a stable product and the contribution of thiol groups to protein cross-linking depend on the methylglyoxal concentration. The product formed in the reaction of thiol and an insufficient quantity of methylglyoxal (compared to the concentrations of the groups accessible for modification) participates to a significant extent (4 %) to protein cross-linking. Metformin applied in equimolar concentration with methylglyoxal prevents its reaction with amino and guanidino groups but, however, not with thiol groups.
Activity of carbon supported Pt3Ru2 nanocatalyst in CO oxidation
Authors: Popovic Ksenija , Lovic Jelena , Tripkovic Amalija , Olszewski Piotr
Published: September 2009

The electrocatalytic activity of Pt3Ru2/C nanocatalyst toward the electro-oxidation of bulk CO was examined in acid and alkaline solution at ambient temperature using the thin-film, rotating disk electrode (RDE) method. The catalyst was characterized by XRD analysis. The XRD pattern revealed that the Pt3Ru2/C catalyst consisted of two structures, i.e., Pt-Ru-fcc and Ruhcp (a solid solution of Ru in Pt and a small amount of Ru or a solid solution of Pt in Ru). Electrocatalytic activities were measured by applying potentiodynamic and steady state techniques. The oxidation of CO on the Pt3Ru2/C catalyst was influenced by pH and anions from the supporting electrolytes. The Pt3Ru2/C was more active in alkaline than in acid solution, as well as in perchloric than in sulfuric acid. Comparison of CO oxidation on Pt3Ru2/C and Pt/C revealed that the Pt3Ru2/C was more active than Pt/C in acid solution, while both catalysts had a similar activity in alkaline solution.
Densification strain rate in sintering of Tho2 and ThO2-0.25% Nb2O5 pellets
Authors: Kutty T.R.G. , Khan K.B. , Kumar A. , Kamath H.S.
Published: September 2009

The densification behavior of ThO2 and ThO2 containing 0.25%Nb2O5 powder compacts was studied with the help of a high temperature push-rod type dilatometer. From the temperature versus density plots, densification strain rate, (1/?)(d?/dt), were calculated. It was observed that the addition of Nb2O5 to ThO2 has caused a drastic increase in densification strain rate in the density range of 76 to 82% of T.D. A five-fold increase in the values of strain rate for ThO2-0.25%Nb2O5 in comparison to pure ThO2 was observed in the temperature range of 1300 to 1350oC. The decrease in the densification strain rate for ThO2- 0.25% Nb2O5 (composition in wt%) at high densities may be attributed to the grain size effect.
Morphology and microstructure of annealed Ni-Co alloy powders electrodeposited on copper substrates
Authors: Rafailovic L.D. , Maricic A.M. , Artner W. , Nauer G.E. , Minic D.M.
Published: September 2009

Nickel and cobalt alloy powders from two different electrolyte compositions were obtained by electrodeposition from an ammonium sulfate solution. The structure of Ni-Co deposits formed by electrodeposition at a galvanostatic regime and the influence of current density and the bath composition were studied by SEM, DSC and X-ray diffraction methods. It was shown that the microstructure and morphology of the powders depended on the deposition current density as well as bath composition. Both, bath composition and current density affect strongly the deposit growth mechanism and the deposit composition, microstructure, grain size and surface morphology. It was found that the overpotential significantly affects the structure of the formed deposits. When electrodeposition was performed far from equilibrium conditions face-centered cubic (FCC) cobalt was deposited while at low overpotential hexagonal close packed (HCP) Co was formed with a lower rate of hydrogen evolution. The increase of HCP phase in the nanocrystalline deposits was caused by increase of the Co content in the powder as well by decrease of the deposition current density. It was shown that the powders change their structure in the temperature interval from 300?C to 600?C. In Co rich samples, structural changes during heating were attributed to the phase transformation of HCP to FCC.
In-situ processing of TiB2 nanoparticle-reinforced copper matrix composites
Authors: Bozic D. , Cvijovic-Alagic I. , Dimcic B. , Stasic J. , Rajkovic V.
Published: September 2009

In order to produce the composite powder analyzed in this paper, two prealloys were melted and afterwards gas atomized. The obtained TiB2-reinforced copper powder was consolidated by hot isostatic pressing (HIP). Since it is known that a decrease in the size of the reinforcing phase can cause an increase in hardness of composites, the main aim of the experimental work was to obtain as small particles of the dispersed phase as possible by using standard powder metallurgy techniques. Microstructure and microhardness of the ascast prealloys, as-atomized powder and HIP-ed compacts were examined. The results of these examinations revealed that TiB2 particles about 10 nm in size were in-situ formed and homogenously dispersed in the copper matrix. As a consequence of the TiB2 formation, the microhardness of Cu-TiB2 composite was significantly improved.
Fabrication and fibre matrix interface characteristics of Cu/C(Fe) composite
Authors: Li Y. , Bai P. , Li Y.
Published: September 2009

Cu/C composites were successfully fabricated by three step electro-deposition. The effects of hot pressure temperature and alloy element Fe on the interface characteristic of Cu/C composite were investigated. The results showed that the hot pressure temperature and interface characteristic have a great effect on mechanical properties of the composite. The tensile strength and hardness increase firstly and then decrease with the increasing of hot pressure temperature, and a tensile rupture appears when the hot pressure temperature is 650, 700 and 900oC. The addition of alloy element Fe not only improves the tensile strength and the lateral shear strength of the Cu/C composite, but also changes the interface bond type from the physical bond type to the chemical bond type.
Using Patient Safety Science to Explore Strategies for Improving Safety in Intravenous Medication Administration
Authors: Franklin Michelle
Published: September 2009

Harm is more likely to result from errors in intravenous (IV) administration than through any other routes of administration. Infusion therapies are delivered in a variety of settings every day, including hospitals, home care settings, long-term care facilities, occupational health facilities, outpatient clinics, and physician offices. Understanding the basic principles of patient safety and developing strategies to reduce risk and severity are critical to improving the safety of IV medication administration. Consistent implementation of accepted strategies to prevent error is long overdue in the practice of IV medication administration. This article challenges the reader to develop a better understanding of patient-safety science, thoroughly investigate the causes of IV medication administration errors, and develop processes to mitigate the recurrence of similar errors.
A Nurse-Driven Peripherally Inserted Central CatheterTeam Exhibits Excellence Through Teamwork
Authors: Ean Renee , Kirmse Jane , Roslien Jennifer , Dickerson Kate , Grimes Elizabeth , Lowrie Angela , Woodman Kim
Published: September 2009

Studies have demonstrated that a dedicated peripherally inserted central catheter (PICC) team can reduce costs, lead to efficient use of staff time, improve patient outcomes, and improve organizational performance. A dedicated, nurse-driven PICC team at the authors' facility has demonstrated excellence through teamwork. Over the past three years, the PICC team has made significant strides in the quality of service provided to patients. The goals of the team consisted of (1) improving PICC-placement success rates; (2) developing an electronic database to track patient outcomes; (3) constructing protocols and guidelines to improve efficiency, appropriate use of PICC lines, and patient safety; and (4) pursuing collaborative research projects, publications, and presentations at the local and national level.
The Advantages of a Precision-engineered Securement Device for Fixation of Arterial Pressure-monitoring Catheters
Authors: Stephenson Catharine
Published: September 2009

A prospective, sequential, controlled trial was conducted to evaluate the clinical and cost consequences of securing arterial catheters with a precision-engineered securement device compared with tape and transparent membrane dressing (TMD). Tape and TMD securement resulted in an unscheduled catheter restart rate of 25%; the study device resulted in an unscheduled catheter restart rate of 12.8%. The difference was highly significant (P < .001).
The Importance of Child Life and Pain Management During Vascular Access Procedures in Pediatrics
Authors: Heckler-Medina Gail A.
Published: September 2009

The author asks of the reader: Have you ever been called to start a peripheral intravenous (IV) catheter or place a peripherally inserted central catheter (PICC) in a child, and you wished someone else could do it? Performing vascular access procedures on children is considered by many one of the most stressful and difficult jobs. This article discusses the role of certified child life specialists (CCLSs) and some of the techniques used to assist children in coping with painful procedures as well as the necessity for proper assessment and pain management. The goal of this article is to eliminate the uncertainty of performing these procedures on pediatric patients. By making a few changes in your practice, one could dramatically increase successful outcomes and improve the overall quality of care provided to the patient.
Trimming of Peripherally Inserted Central Catheters: The End Result
Authors: Pettit Janet
Published: September 2009

A debate surfaced in the neonatal literature over two years ago questioning the safety and efficacy of trimming peripherally inserted central catheters (PICCs) prior to insertion. An investigation was undertaken to define the risks and benefits of doing so and evaluate the methods of trimming PICCs. When trimmed by 1 of 3 methods, conclusive evidence revealed that the method of catheter trimming affects the integrity of the catheter tip. Additional study is required to determine whether catheter tip alteration impacts patient outcomes.
Vascular Access Nursing Practice, Standards of Care, and Strategies to Prevent Infection: A Review of Skin Cleansing Agents and Dressing Materials (Part I of a 3-Part Series)
Authors: Richardson Deborah
Published: September 2009

This three-part series of articles (parts 2 and 3 will be published in the Spring and Summer 2007 journal issues, respectively) will include information appropriate for the novice and the expert vascular access nurse. The series will include primers on vascular access devices, along with review of skin cleansing agents, dressing materials, catheter flush solutions, and injection caps. The focus of the article series will be the issue of catheter-related bloodstream infection, practice, technologies developed to prevent or decrease infections, current standards, and guidelines and preventive strategies.
Heparin Locking for Central Venous Catheters
Authors: Hadaway Lynn
Published: September 2009

Traditionally, heparin-lock solution has been used with all central venous catheters. The introduction of new technology calling for the elimination of heparin and the growing concerns about the use of heparin have caused many health care professionals to question its continued use for this purpose. This literature review attempts to answer the most common questions using available research; however, there continues to be more questions than answers. At present, it appears that some farm of anticoagulant will produce more patent catheters, and heparin-lock solution is the only product commercially available. This situation drives the need for a careful assessment of patients' needs prior to abandoning the use of heparin.
Complications of Vascular Access Device Terminal Tip Placement: A Case Study and Review of Subsequent Legal Action
Authors: Moureau Nancy L. , Zonderman Ann
Published: September 2009

A patient experienced complications following insertion and use of 2 similar vascular access devices with tip termination apparently in the subclavian veins. The thrombotic complications that developed were identified and reported in the first incident (a) as an occluded catheter, and then (b) as bleeding complications with delayed reporting for 8 days with the second catheter. The result was symptomatic deep vein thrombosis, thoracic outlet syndrome, and permanent nerve damage in both right and left extremities used for the venous catheter. The patient brought charges of malpractice against the hospital, the home care company, one nurse, and the manufacturer, alleging permanent nerve damage, venous occlusion, and chronic pain syndromes associated with both upper extremities. During the subsequent trial, evidence of permanent loss of function to the patient's left arm and chronic pain to both arms was presented through documentation of loss of fitness and inability to perform actions necessary to his chosen career as a pilot. The pain and loss of function were directly related to terminal tip placement of the catheter and care provided in conjunction with the venous catheter. The jury trial awarded the patient a final judgment of $7.15 million, with the hospital 55% liable and 45% liability among the other defendants. The jury also added some hospital physicians to the liability of the treatment and resulting patient harm. Nurses caring for patients have a duty to assess and evaluate the patient for complications on an ongoing basis, administer the prescribed therapy, and consistently provide communication with the primary physician specific to the assessment findings. A specialized nurse or certified intravenous nurse (CRNI) is held to a higher level of knowledge, understanding, and function. In this case, a CRNI was providing care for the patient both through hospital and outpatient home care services. Medical professionals and hospitals can reduce the likelihood of liability related to adverse events with venous catheters by acquisition of current education on the devices they insert and maintain; by updating and adhering to policies and procedures based on Standards of Practice and manufacturer instructions for use; by thorough documentation of care; and by conscientious reporting of patient clinical signs and symptoms. The goal of achieving safe patient care with vascular access devices is only possible through consistent education processes with all associated clinical staff.
Catheter-Related Infections in a Canadian Home Total Parenteral Nutrition Program: A Prospective Study Using U.S. Centers for Disease Control and Prevention Criteria
Authors: Saqui Olivia , Raman Maitreyi , Chang Albert , Allard Johane P.
Published: September 2009

The most frequent home parenteral nutrition complication is central venous catheter infection. The authors sought to determine the rate and types of bloodstream infections in a Canadian home parenteral nutrition program. Methods: Bloodstream infection was diagnosed if all following criteria were present: (1) one or more positive blood cultures were found, (2) antimicrobial therapy or catheter was removed, and (3) there were no other infections. Results: Between April 1, 1996, and April 30, 1997, 43 patients from the Home Parenteral Nutrition Program at Toronto General Hospital participated in a multicenter study in which a total of 355 patients receiving home infusion therapy for various reasons were enrolled. From these 43 patients, there were 37 infections in 19 home parenteral nutrition patients. The infection rate was 2.3 per 1000 catheter days. The common infecting organism was coagulase-negative Staphylococcus. Conclusion: In this prospective study involving patients receiving home parenteral nutrition, although the information is 10 years old, the infection rate of 2.3 per 1000 catheter days is lower than most recent studies involving patients receiving total parenteral nutrition in the hospital or at home with a similar common infecting organism of coagulase-negative Staphylococcus.
Intermittent Intravenous Administration Sets: Survey of Current Practices
Authors: Hadaway Lynn
Published: September 2009

The practice of using intravenous (IV) administration sets for intermittent infusion is subject to much controversy and there is no scientific data to validate the practice. To get an idea of this practice, an online survey was sent to approximately 4000 nurses, with 361 responding. The results highlight the vast differences in practice between the clinical settings of the available studies and how these sets are currently used. Although no recommendations for practice can be drawn from these data, they emphasize the urgent need for research on the use of intermittent administration sets and their contribution to the incidence of catheter-related bloodstream infection.
Nursing Beyond the “Process”: Collegiality and Consultation Improves Outcomes by Protecting the Tissue Integrity of PICC Insertion Sites
Authors: Dawson Robert B.
Published: September 2009

On a daily basis vascular access nurses are presented with complex patient care issues involving intravenous therapy. The nursing process as an instrument to organize nursing care is valuable; however, is it enough to positively affect patient outcomes? Nursing beyond the fundamental process requires the intent to advocate and protect the patient from unnecessary risk or harm. A patient with impaired tissue integrity from epidermolysis bullosa required a nurse specialist whose practice included advocacy, collegiality and consultation in order to protect a PICC insertion site and prevent complications. The intervention included the use of a soft silicone contact layer (Mepitel®) and a transparent semi-permeable membrane dressing (Tegaderm®). A new clinical process was born from the collaboration of two nursing professionals and it positively impacted patient outcomes. This is a professional approach to nursing care that is under utilized.
Potential Value of Vitamin E in Cancer Patients with Venous Access Devices
Authors: Chernecky Cynthia , Macklin Denise , Nugent Katherine , Waller Jennifer
Published: September 2009

Background: Vitamin E has antiplatelet, fibrinolytic and endotoxin properties that may help avoid the problems of occlusion or inability to withdraw blood from port VADs.

Purpose: Disseminate information about the non-traditional therapeutic use of vitamin E associated with care of Venous Access Devices (VAD) in patients with cancer.

Methodology: In-person focus groups. Sample of 22 cancer patients who had port Venous Access Devices (VAD).

Findings: Fourteen percent (N = 3) of patients felt that taking vitamin E, 400 -800 IU per day orally, in capsule form, avoided the problems of occlusion or inability to withdraw blood from their current VAD.

Practice Implications: The effects of vitamin E on occlusion and inability to withdraw blood in caring for patients who have port VADs, requires further investigation.
Colored scalar in a chromomagnetic field
Authors: Turkoz Shemsettin , Mamedov Shahin , Ciftci Abbas
Published: September 2009

The motion of colored scalar particles in a constant color magnetic field is considered. The Klein-Gordon equation is solved in this background and the energy spectrum is quantized by boundary conditions. The unitary transformation diagonalizing this equation and the states with definite energy are found.
Double passage of electromagnetic waves through magnetized plasma: approximation of independent normal waves
Authors: Kravtsov Yury , Bieg Bohdan
Published: September 2009

Polarization properties of electromagnetic waves, double-passed through magnetized plasma, are studied. Analyses are performed in the case of non-interacting normal modes, propagating in homogeneous and weakly inhomogeneous plasmas, and for three kinds of reflectors: metallic plane, 2D corner retro-reflector (2D-CR), and cubic corner retro-reflector (CCR). It is shown that an electromagnetic wave, reflected from a metallic plane and from a CCR, contains only “velocity-preserving” channels, whose phases are doubled in comparison with those of a single-passage propagation. At the same time, an electromagnetic wave reflected from a 2D-CR is shown to contain both “velocity-preserving” and “velocity-converting” channels, the latter converting the fast wave into the slow one and vice-versa. One characteristic feature of “velocity-converting” channels is that they reproduce the initial polarization state near the source, which might be of practical interest for plasma interferometry. In the case of circularly polarized modes, “velocity-preserving” channels completely disappear, and only “velocity-converting” channels are to be found.
The intrabody targeting of hTERT attenuates the immortality of cancer cells
Authors: Zhu Xiangying , Yang Nan , Cai Jianguo , Yang Guimei , Liang Shenghua , Ren Daming
Published: September 2009

hTERT (human telomerase reverse transcriptase) plays a key role in the process of cell immortalization. Overexpression of hTERT has been implicated in 85% of malignant tumors and offers a specific target for cancer therapy. In this paper, we describe an effective approach using a single-chain variable fragment (scFv) intrabody derived from monoclonal hybridoma directed against hTERT to attenuate the immortalization of human uterine cervix and hepatoma cells. The scFv we constructed had a high affinity to hTERT, and specifically neutralized over 70% of telomere synthesis activity, thereby inhibiting the viability and proliferation of the cancer cells. Our results indicate that this anti-hTERT intrabody is a promising tool to target hTERT and intervene in the immortalization process of cancer cells.
Old and New ' Anschauungen in der Anorganischen Chemie' A Homage to Alfred Werner's Book and Intuition: Part I. Alfred Werner's Book and Coordination Theory
Authors: Berke Heinz
Published: September 2009

Alfred Werner (1866–1919) is regarded as the founder of coordination chemistry. He was the author of the book entitled 'Neuere Anschauungen auf dem Gebiete der Anorganischen Chemie' (New Perspectives in Inorganic Chemistry) which guided generations of chemists in research and
teaching. This book was recently awarded the 'Citation for Chemical Breakthrough' prize from the Division of the History of Chemistry of the American Chemical Society. This article is the first of three dedicated to Werner's life and works.
UZH's Chem MusEum e-Learning Concept
Authors: Weber Heidi C. , Macrina Marina
Published: September 2009

The Chem MusEum of the University of Zurich is the latest project of the Chemical Institutes for living history in terms of an interactive online exhibition.
An inventory of active subglacial lakes in Antarctica detected by ICESat (2003–2008)
Authors: Smith Benjamin E. , Fricker Helen A. , Joughin Ian R. , Tulaczyk Slawek
Published: September 2009

Through the detection of surface deformation in response to water movement, recent satellite studies have demonstrated the existence of subglacial lakes in Antarctica that fill and drain on timescales of months to years. These studies, however, were confined to specific regions of the ice sheet. Here we present the first comprehensive study of these ‘active’ lakes for the Antarctic ice sheet north of 86° S, based on 4.5 years (2003–08) of NASA’s Ice, Cloud and land Elevation Satellite (ICESat) laser altimeter data. Our analysis has detected 124 lakes that were active during this period, and we estimate volume changes for each lake. The ICESat-detected lakes are prevalent in coastal Antarctica, and are present under most of the largest ice-stream catchments. Lakes sometimes appear to transfer water from one to another, but also often exchange water with distributed sources undetectable by ICESat, suggesting that the lakes may provide water to or withdraw water from the hydrologic systems that lubricate glacier flow. Thus, these reservoirs may contribute pulses of water to produce rapid temporal changes in glacier speeds, but also may withdraw water at other times to slow flow.
Spatially integrated geodetic glacier mass balance and its uncertainty based on geostatistical analysis: application to the western Svartisen ice cap, Norway
Authors: Rolstad C. , Haug T. , Denby B.
Published: September 2009

Estimates of glacier mass balance using geodetic methods can differ significantly from estimates using direct glaciological field-based measurements. To determine if such differences are real or methodological, there is a need to improve uncertainty estimates in both methods. In this paper, we focus on the uncertainty of geodetic methods and describe a geostatistical technique that takes into account the spatial correlation of the elevation differences when calculating spatially averaged elevation changes. We apply this method to the western Svartisen ice cap, Norway, using elevation differences from the surrounding bedrock derived from stereophotogrammetry. We show that the uncertainty is not only dependent on the standard error of the individual elevation differences but is also dependent on the size of the averaging area and the scale of the spatial correlation. To assess if the geostatistical analysis made over bedrock is applicable to glacier surfaces, we use concurrent photogrammetrical and laser scanning data from bedrock and a range of glacier surfaces to evaluate the dependency of the geostatistical analysis on the surface type. The estimated geodetic mass balance, and its uncertainty, is −2.6 ± 0.9 m w.e. for the period 1968–85, and −2.0 ± 2.2 m w.e. for 1985–2002.
A new index of glacier area change: a tool for glacier monitoring
Authors: Dyurgerov Mark , Meier Mark F. , Bahr David B.
Published: September 2009

Since the mid-19th century, most glaciers have been losing area and volume. This loss of area has not been homogeneous in time and space, and direct observations are sparse, making regional and global estimates of glacier change difficult. This paper focuses on developing a single index for monitoring glacier change, one that would be particularly useful for remote-sensing applications. We combine the results of direct glacier mass-balance observations B, total glacier area S and accumulation area Sc derived from maps or remotely sensed images. Using the accumulation–area ratio (AAR = Sc/S), we note the differences between observed AAR, time-averaged 〈AAR〉 and the equilibrium state AAR0, as determined by its value at B = 0 from a regression of B(AAR). We suggest that αd = (〈AAR〉 – AAR0)/AAR0 quantifies the difference between the currently observed state of glaciers and their equilibrium state and measures the delay in the dynamic response of S relative to the climatic response of Sc. Using all available observations for the period 1961–2004, αd ≈ −65% for tropical glaciers, which implies their rapid shrinkage as S continues to decrease and ‘catch up’ with Sc. During the same period, mid-latitude and polar glaciers show less negative values of αd. Of 86 glaciers from all latitudes and regions, only 11 show positive αd at any time between 1961 and 2004. Averaged over 1961–2004, αd is −15.1 ± 2.2%, and 〈B〉 is −360 ± 42 mm a−1 w.e. Values for AAR0 range between about 40% and 80%, but the bulk of the equilibrium values are between 50% and 60%. The average AAR0 is 57.9 ± 0.9% and has remained stable over time (the equilibrium AAR has not changed with climate). Overall, the observed negative αd suggests a committed retreat of glaciers and their continuing contribution to sea level even if global temperature is held constant.
A Multicenter, Randomized, Open-Labeled, Parallel Group Trial of Sildenafil in Alcohol-Associated Erectile Dysfunction: The Impact on Psychosocial Outcomes
Authors: Ponizovsky Alexander M. , Averbuch Lev , Radomislensky Ira , Grinshpoon Alexander
Published: September 2009

To examine the effect of sildenafil on erectile dysfunction (ED) and psychosocial outcomes in alcohol-dependent (AD) men, 108 men with these diagnoses were randomly assigned to either take sildenafil (50 mg) as add-on to standard treatment for AD, or the same treatment without sildenafil, for 12 weeks. Only 50 patients in sildenafil group and 51 in control group twice completed the International Index of Erectile Function (IIEF) and a battery of self-report questionnaires. IIEF scores and psychosocial functioning, self-esteem and support from friends improved only for sildenafil-treated patients (P < 0.001). The high effect sizes suggest that the observed benefits are unlikely to be a placebo effect, although their unspecific nature could not be ruled out. In men with ED associated with AD, sildenafil improves both ED and psychosocial outcomes. Further placebo-controlled clinical trial is warranted.
Lysis of Microcystis aeruginosa with Extracts from Chinese Medicinal Herbs
Authors: Yang Jing-Dong , Hu Liang-Bin , Zhou Wei , Yin Yu-Fen , Chen Jian , Shi Zhi-Qi
Published: September 2009

Boiling water extracts of 66 selected Chinese medicinal herbs were screened for their anticyanobaterial activity against Microcystis aeruginosa by the soft-agar overlayer (SAO) method. Results indicated that extracts from 16 materials could inhibit the growth of this bacterial species. Among these anticyanobacterial samples, eight extracts showed low minimum inhibitory concentrations (MIC), including four extracts with MICs between 1 and 6 mg/mL, and four extracts with MICs < 1 mg/mL which could be considered useful to prevent the outbreak of cyanobacteria before the appearance of cyanobacterial blooms. Further study showed that three extracts with MIC values < 1 mg/mL induced intensive chlorophyll-a lysis within 7 days at the MIC. The results suggested that highly efficient anticyanobacterial compounds must be involved in the inhibitory activities. The final results indicated these three extracts (from Malaphis chinensis, Cynips gallae-tinctoriae and Fructus mume) had the potential to be developed as algicides due to their remarkably anticyanobacterial activities.
Nasal Delivery of High Molecular Weight Drugs
Authors: Ozsoy Yıldız , Gungor Sevgi , Cevher Erdal
Published: September 2009

Nasal drug delivery may be used for either local or systemic effects. Low molecular weight drugs with are rapidly absorbed through nasal mucosa. The main reasons for this are the high permeability, fairly wide absorption area, porous and thin endothelial basement membrane of the nasal epithelium. Despite the many advantages of the nasal route, limitations such as the high molecular weight (HMW) of drugs may impede drug absorption through the nasal mucosa. Recent studies have focused particularly on the nasal application of HMW therapeutic agents such as peptide-protein drugs and vaccines intended for systemic effects. Due to their hydrophilic structure, the nasal bioavailability of peptide and protein drugs is normally less than 1%. Besides their weak mucosal membrane permeability and enzymatic degradation in nasal mucosa, these drugs are rapidly cleared from the nasal cavity after administration because of mucociliary clearance. There are many approaches for increasing the residence time of drug formulations in the nasal cavity resulting in enhanced drug absorption. In this review article, nasal route and transport mechanisms across the nasal mucosa will be briefly presented. In the second part, current studies regarding the nasal application of macromolecular drugs and vaccines with nanoand micro-particulate carrier systems will be summarised.