Ideal Substance Research Articles

High-Field ESR Measurements of S=1/2 Kagome Lattice Antiferromagnet BaCu3V2O8(OH)2

High-field electron spin resonance (ESR) measurements have been performed on vesignieite BaCu 3 V 2 O 8 (OH) 2 , which is considered as a nearly ideal model substance of S =1/2 kagome antiferromagnet, in the temperature region from 1.9 to 265 K. The frequency region is from 60 to 360 GHz and the applied pulsed magnetic field is up to 16 T. Observed g -value and linewidth show the increase below 20 K, which suggest the development of the short range order. Moreover, a gapless spin liquid ground state is suggested from the frequency–field relation at 1.9 K.

Uso de carbonos pirolíticos (Durasphere) no tratamento da insuficiência glótica: estudo experimental em cães

Nenhum tecido ou substância ideal foi encontrado para a injecao em pregas vocais. O objetivo deste estudo prospectivo foi avaliar o uso do Durasphere como substância de injecao na prega vocal canina. MATERIAIS E METODOS: Em seis caes adultos foram injetados 0,3mL de Durasphere no terco medio da prega vocal direita no musculo tireoaritenoideo e 0,3mL de soro fisiologico na prega contralateral. Os animais foram sacrificados apos 7 dias (tres caes) e 90 dias (tres caes). Analisamos os processos inflamatorios no musculo vocal e na lâmina propria das pregas vocais. RESULTADOS: No musculo vocal com Durasphere havia uma inflamacao significativamente maior que no musculo controle, formouse um infiltrado linfomononuclear moderado apos 7 dias e leve apos 90 dias. Nao observamos formacao de corpos estranhos ou granulomas. Ja na lâmina propria houve um processo inflamatorio leve nos dois grupos, sem diferenca entre eles. CONCLUSAO: Trata-se de uma substância com biocompatibilidade comprovada em humanos, com resultados preliminares e ineditos de sua injecao em pregas vocais caninas que causou um processo inflamatorio moderado no musculo vocal apos 7 dias e leve apos 90 dias, sem formacao de corpos estranhos ou granulomas.

Use of pyrolytic carbon coated beads (Durasphere) to treat glottic failure: an experimental study in dogs

SummaryThere is no ideal tissue or substance to be injected in the vocal folds. The objective of the present study was to assess the use of Durasphere in canine vocal fold injection.Materials and Methodsin six adult dogs we injected 0.3 mL of Durasphere in the middle third of the thyroarytenoid muscle and 0.3 mL of saline solution in the contralateral vocal fold. The animals were slaughtered after seven days (three dogs) and after 90 days (three dogs). We analyzed the inflammatory process in the vocal fold and in the lamina propria of the vocal folds.Resultsin the vocal muscle which received Durasphere there was a significantly more intense inflammation when compared to the control muscle - there was a moderate lymphomodular infiltrate after seven days and mild after 90 days. We did not observe foreign bodies nor granulomas. On the lamina propria there was a mild inflammatory process in the two groups, without difference between them.Conclusionthis is a substance of proven biocompatibility in humans, with preliminary and unprecedented results and its injection in canine vocal folds caused a moderate inflammatory process after seven days and mild after 90 days, without foreign bodies or granuloma formation.

Invited Commentary

If you have not already heard of the Acute Kidney Injury Network (AKIN), then let this commentary serve as your introduction. AKIN is a large and rapidly growing collaborative organization (www.akinet.org), primarily at this point involving critical care and nephrology societies (the Society of Cardiovascular Anesthesiologists will be the first perioperative organization to join). The goal of AKIN is to advance knowledge that will lead to evidence-based therapies for the treatment and prevention of acute kidney injury (AKI) AKI is the term coined by AKIN to replace “acute renal injury.” This change parallels a strategic approach to AKI investigation similar to “acute myocardial infarction” that has been so successful in improving patient care. AKIN is systematically outlining hurdles to progress—one of the earliest was an absence of a broadly accepted definition for AKI—and they have since proposed the widely accepted AKIN criteria based on creatinine rise or oliguria thresholds, or both. As troponin and creatine kinase-MB fraction have facilitated more timely interventions in the treatment of acute myocardial infarction than the traditional electrocardiogram Q wave, so now is the hope that early AKI biomarkers will revolutionize the field of AKI therapy relative to creatinine rise or dialysis. The article by Haase and colleagues [1Haase M. Bellomo R. Devarajan P. et al.Novel biomarkers early predict the severity of acute kidney injury after cardiac surgery in adults.Ann Thorac Surg. 2009; 88: 124-130Abstract Full Text Full Text PDF PubMed Scopus (157) Google Scholar] nicely summarizes progress in the field of early AKI biomarker development. Although some new tools simply aim to substitute a more ideal creatinine-like substance for estimates of renal filtration (eg, cystatin C), most early markers relate to one of the three early consequences of AKI: tubular cell dysfunction, tubular cell damage, and the adaptive kidney stress response. The hope is that the prompt appearance of biomarkers will facilitate timely AKI risk identification, surveillance (ie, recognition of states such as prerenal azotemia), diagnosis, and prognosis. Strategic approaches such as focused multitest panels may improve the usefulness and precision of AKI biomarkers to address issues such as the timing of onset, grade of problem, and even the type of AKI, such as ischemic vs inflammatory. Preliminary studies indicate that these goals are realistic; however, three caveats are relevant to AKI biomarker development and cardiac surgery. First, there is confusion surrounding the relationship of AKI biomarkers with end organ protection and outcome. We have learned from aprotinin that even when interventions produce favorable changes in hemostasis biomarkers and selected end organ function such as bleeding and transfusion, this should always be followed by trials confirming better overall outcome. Biomarker studies alone are rarely sufficient reason to change practice. Second, oliguria, a criteria for AKI according to AKIN, is likely to prove much less associated with overall adverse outcome perioperatively compared with other settings. Finally, a confusing but apparently benign interaction between lysine analogue antifibrinolytic agents (ie, ε-aminocaproic acid, tranexamic acid) and the proximal renal tubular transport mechanism that causes wasting into the urine of filtered microglobulins and other low-molecular-weight proteins can give a false impression of renal tubular injury. Proteinuria always occurs but also resolves within minutes of discontinuing these drugs. The major hope is that improvements in monitoring with biomarkers will translate into better prevention, treatment, and outcome from AKI, something that has been disappointingly absent during the past half-century since perioperative acute renal failure was first described. Novel Biomarkers Early Predict the Severity of Acute Kidney Injury After Cardiac Surgery in AdultsThe Annals of Thoracic SurgeryVol. 88Issue 1PreviewThe purpose of this study was to investigate the ability of neutrophil gelatinase-associated lipocalin (NGAL), cystatin C, and their combination in predicting the duration and severity of acute kidney injury (AKI) after cardiac surgery in adults. Full-Text PDF

Lutein supplementation ‐ the mechanisms

AbstractLutein and zeaxanthin are responsible for the formation of the macular pigment. There is a decrease of macular pigment density with increasing age. There are several studies showing that loss of macular pigment density is associated with an increased risk of age related macular degeneration (AMD). Therefore macular pigment density seems to have a protective effect of the macular from developing AMD. The best characterized role of lutein/zeaxanthin in the protection is the ability to absorb damaging blue light. Furthermore it is known from several in vitro and chemical investigations that lutein/zeaxanthin have anitoxidative properties. Based on the fact, that oxidative plays a major role in the pathogenesis, lutein/zeaxanthin could also protect the macular from damaging free radicals. A natural response of oxidative stress is the process of inflammation. Based on genetic studies and morphological studies AMD revealed the involvement of a subclinical inflammation in AMD pathogenesis. Lutein/zexaxanthin have anti‐inflammatory properties. This fact may explain the recently described inhibition of choridal neovascularisation in an experimental model of wet form of AMD. Taken together lutein/zexaxanthin are ideal candidates to protect the macular from damaging blue light, oxidative stress and subclinical inflammation. Based on these findings lutein/zeaxanthin seem to be ideal substance to prevent and stop progression of AMD.

Charakteristika und Auswahl der Substanzen

Prior to an operation, patients experience a high degree of stress and internal tension. Preoperative drug administration (premedication) is intended to reduce these stresses through anxiolytic and sedative effects. On account of their good anxiolytic actions, there excellent tolerability and only few side effects benzodiazepines are most frequently used for this purpose. To support the induction and continuation of sleep, premedication is usually initiated in the evening before operation with the administration of a benzodiazepine with middle- or long-term activity. The standard drug for the day of operation is the short-acting benzodiazepine midazolam, under the action of which the patient may be transferred to the operation room in a drowsy and calm state. The onset of action of drugs applied as preoperative medication is delayed. Thus, it is of major importance that the premedication be administered at the appropriate time point so that the patient really is shielded fro preoperative stress at the time of the drug's optimal effect. Although midazolam is not the ideal substance for all situations where an anxiolytic premedication is needed, with the exception of a few special indications, no decisive advantages over other drugs have been demonstrated in comparative trials.

Accelerated expansion of the Universe and multidimensional theory of gravitation

A condition for accelerated expansion of the Universe is derived from multidimensional formulas of gravitation, which is a generalization of the general theory of relativity for n dimensions. The model of a one-component ideal isotropic substance with a power-law diagonal metric is used as initial one. Restrictions on the state equations of our 3D space and accompanying additional dimensions are obtained.

Carboxymethylcellulose as a new carrier substance for intravitreal injection of reproducible amounts of triamcinolone

Intravitreal application of triamcinolone acetonide has become increasingly popular for the treatment of various retinal disorders. However, dosage, mode of preparation and application differ worldwide. The aim of this study was to find a safe vehicle that would allow intravitreal injection of an exact amount of triamcinolone acetonide without potentially retinotoxic preservatives. Solutions of triamcinolone acetonide with a theoretical concentration of 4 mg/0.2 ml were prepared following one sedimentation (A) and two filtration (B, C) methods. In addition, a filtration method using carboxymethylcellulose 2% as a carrier (D) was established. During processing and after injection into an eye model, the crystals were quantified by weight and high-performance liquid chromatography (HPLC), and, hence, the rate of crystal loss during this process was determined. The initial preparation contained 93-106% of the calculated quantity. Method A, containing the entire vehicle, delivered 45%+/-7.3% of the target quantity to the eye model, whereas the vehicle-free methods B and C delivered 15%+/-6.9% and 11%+/-3.2%, respectively. Using carboxymethylcellulose 2% as a preservative-free vehicle, we found 93%+/-3.7% of the calculated amount in the eye model. The missing crystals were mainly sticking to the walls of the syringes and needles used for transfer. Common methods for preparing triamcinolone acetonide vary in the amount of drug actually injected intravitreally. Carboxymethylcellulose is an ideal carrier substance for intravitreal application of an exact dose of triamcinolone acetonide without preservatives.

The use of the kidneys in secular and ritual practices according to ancient Greek and Byzantine texts

The use of kidneys in secular and spiritual practices was very common for centuries. In this article we present some references on their employment as sacrificial offers, as plain food or as a source for medicaments. Our material derives from Greek texts of the Classical, Hellenistic, Roman, and Byzantine eras. Relevant extracts from the Old Testament are also included, as they have become part of a common cultural heritage in that period of syncretism, when Jews were Hellenized and Greeks orientized. From the fragments cited in this article, it is obvious that the practical use of kidneys by priests, doctors, and lay persons in the periods under discussion was widespread. The sacrificial offering was based on the religious significance of the organ. The dietary consumption of the kidneys was limited by their function as urine producers. Their medicinal use was dictated first, by the abundance of the adipose tissue surrounding them, which was an ideal warming and binding substance. Second, it may be explained by the deeply rooted conviction that eating a particular organ led to the incorporation of its strength, thus protecting the corresponding eater's organs. Those practices should not surprise us in view of their corresponding modern use. Currently, kidney donors offer their organs in a sacrificial gesture, kidneys are consumed as a delicacy worldwide, and renal tissue is therapeutically used in transplantations and, until very recently, as a source for hormonal substances.

Raman Analysis of Microscopic Residual Stresses Stored in the Secondary Phase of Sc<sub>2</sub>O<sub>3</sub>-Doped Si<sub>3</sub>N<sub>4</sub>

Residual stress studies were performed on the intergranular phase of a Sc2O3-doped Si3N4 polycrystal. Sc2O3 additive represents an ideal substance for residual stress analysis because of the intense Raman spectrum of its related silicate (intergranular) phases, which form during sintering. Crystallization of Sc2O3 to Sc2SiO7 during the cooling process after sintering causes a negative volume change at triple pockets of polycrystalline Si3N4 which overlaps mismatches in thermal expansion coefficients between secondary phase and the Si3N4 matrix. Conventional piezo-spectroscopic (PS) stress analyses have usually been limited to measurements in the Si3N4 matrix. In this paper, we show for the first time measurements of residual stresses stored within the secondary phase of Si3N4, using the Raman spectrum of Sc2O3. A change in crack propagation mode from intergranular to transgranular was found after annealing the Sc2O3-doped Si3N4 material, such a difference leading to an embrittlement of the material. Residual stress analysis of the annealed sample revealed that the tensile residual stress stored within the secondary phase was removed, thus explaining why the rising R-curve behavior of the material was substantially suppressed as compared to the as-sintered sample.

Biocompatibility of microparticles into soft tissue fillers

The increasing need for long-lasting injectable soft tissue fillers for the treatment of wrinkles and folds requires a critical discussion of the biocompatibility on a scientific background. Since biological fillers made of collagen and hyaluronic acid will be resorbed over time, copolymer biomaterials with microparticles have been developed in recent years. The microparticles followed special and essential demands because of the interaction with the tissue. In search of an ideal soft tissue filler substance, a variety of biomaterials with microparticles suspended have been created for injecting into dermal defects, into the urethra of patients with urinary incontinence, and in patients with vocal cord insufficiency. The particles differ in chemical composition, surface structure, surface charge, and particle size and evoke different host reactions, accordingly.

Inertial effects and diffusion

Fick’s law of diffusion is equivalent to an equation of motion for an ideal substance in which the thermodynamic driving force is assumed to be balanced by a drag force proportional to drift velocity. Neglect of the inertial force required by Newton’s second law leads to anomalous short-time predictions such as infinite speeds of propagation. Resolution of the propagation anomaly for chemical diffusion is considered for three applications: Knudsen flow in porous materials, interstitial diffusion in elastic solids, and interstitial diffusion in viscoelastic solids. The transients associated with inertial effects for the first two cases occur at very short-times and are typically of little practical significance. Diffusion in viscoelastic solids appears as a possible exception based on observations of linear transport kinetics in ordinary timescales. The constitutive equations for the Maxwell model lead to the prediction that solute-induced dilatations propagate according to the telegraph equation, a widely proposed correction for avoiding the propagation anomaly in standard diffusion theory. The telegraph equation is not universally valid, however. In the case of Knudsen flow, for example, inertial effects give rise to an additional term related to material convection.

A Novel Thermodynamic Relationship Based on Kramers Theory for Studying Enzyme Kinetics under High Viscosity

In most studies of enzyme kinetics it has been found sufficient to use the classical Transition State Theory (TST) of Eyring and others. This theory was based on the solvent being an ideal dilute substance treated as a heat bath. However, enzymes found in organisms adapted to very low (psychrophiles) and very high (thermophiles) temperatures are also subjected to variable solute concentrations and viscosities. Therefore, the TST may not always be applicable to enzyme reactions carried out in various solvents with viscosities ranging from moderate to very high. There have been numerous advances in the theory of chemical reactions in realistic non-ideal solvents such as Kramers Theory. In this paper we wish to propose a modified thermodynamic equation, which have contributions from kcat, Km and the viscosity of the medium in which the enzyme reaction is occurring. These could be very useful for determining the thermodynamics of enzymes catalyzing reactions at temperature extremes in the presence of substrate solutions of different compositions and viscosities.

Lipografting: Autologous Fat Grafting for Total Facial Rejuvenation

Surgeons who perform facial rejuvenation procedures have long recognized the importance of volume enhancement. The primary manifestation of aging is loss of subcutaneous tissue, especially the atrophy of fat, which directly contributes to laxity of skin. Autologous fat transplantation has been attempted for over a century with varying degrees of success but more recent techniques have provided more predictable, reproducible, and even permanent results. Fat is an ideal tissue filler substance because it is living tissue and because it is from the patient's own body it is nonallergenic. My technique has evolved over an 11-year period in more than 1800 patients. The procedure can be performed alone as a total facial rejuvenation or in combination with facelift or other facial surgery. The technique requires minimally traumatic fat harvesting, fat preparation, and multilevel facial infiltration. Excess fat not used in the initial procedure is frozen and stored at -16 degrees C and can be used successfully for minor touch-up procedures. Preoperative evaluation of the patient and their understanding of the benefits and limitations of volume restoration surgery is imperative. Structural improvement to the main support areas of the face in the appropriate aesthetic proportions is of prime importance.

Production of Carbon Mesocell by Arc Electric Discharge

The generation of a carbon nanotube and the first stage of carbon nanotube or carbon fiber formation were investigated in arc electric discharge in a gas mixture of helium and atmosphere with a negative carbon electrode containing lithium or potassium. A carbon stick with lithium and a carbon stick with potassium appeared to accelerate the generation of the carbon nanotube. It was found that the generation of the carbon nanotube is restricted in the range of atmospheric partial pressure from 10 kPa to 20 kPa, and an ideal spherical substance with a size from one hundred nanometers to five micrometers was generated. If the atmospheric partial pressure is lower than that range, the spherical substance changes into a carbon nanotube or carbon fiber. The carbon mesocell, which includes various kinds of elements, can be produced by choosing a carbon stick with additional elements.

Patient-controlled analgesia and sedation in gastrointestinal endoscopy.

Variations in pain threshold, drug tolerance, and visceral sensitivity among patients make it difficult to anticipate the appropriate dose of sedation for gastrointestinal endoscopy. Propofol was recently introduced for sedation in endoscopy and has a rapid onset and offset of action, making it an ideal substance for patient-controlled administration. Several controlled trials have demonstrated that during colonoscopy, patient-controlled application of propofol alone or in combination with various opioids is effective,safe, and yields high patient satisfaction. Target-controlled infusion of propofol has shown encouraging results for prolonged upper endoscopy procedures like endoscopic retrograde cholangio pancreatography.

New aspects of thermal analysis, Part I. Resolution of DSC and means for its optimization

The definitions of the temperature resolution, the so-called resolution of DSC instruments given in literature are discussed. A new definition of the resolution for DSC instruments is presented and outlined. The main characteristic introduced in this new definition is a minimum between two caloric events as a prerequisite of an existing resolution. Possible candidates of test substances have been evaluated. The oligomer n-hexatriacontane is revealing an interesting phenomenon, namely a lambda transition which is in the peak temperature only 2 K lower than the melting temperature of 76°C. The substance was selected as an ideal test substance for the quantification of the resolution of DSC instruments. The lambda transition is a second order process which may reach under certain conditions the saturation of the occurring molecular dislocation within 0.2 K, and after saturation the heat flow rate drops sharply down. Investigations concerning the main characteristics of n-hexatriacontane in respect to the temperatures of transition (lambda transition and melting), to the involved enthalpies, and to the resolution factors were performed as functions of the sample mass and the heating rate. The importance of relevant evaluation procedures increasing the resolution factors of DSC curves are discussed and these procedures are integrated into the testing of the resolution. The necessity for widening the experimental scope from instruments to evaluation procedures is forced by the existence of instruments with built-in signal treatments based on electronic devices and software procedures. A comparison with literature data is outlined for all of the mentioned characteristic values of n-hexatriacontane.

アーク放電法によるカーボンナノ物質の作製に関する研究

The generation of a carbon nanotube was investigated in arc electric discharge in the mixed gas of helium and the atmosphere. A carbon stick and a carbon stick in which lithium is inserted were used for the negative electrode in the arc electric discharge. The carbon stick with litium tends to accelerate the generation of carbon nanotube. It is found that the generation of a carbon nanotube is restricted in the range of atmosphere partial pressure from 10 kPa to 20 kPa and the ideal spherical substance with the size from several hundred nanometers to several micrometers is generated. If the atmosphere partial pressure is lower than those range, the spherical material change into carbon nanotube or carbon fiber.

Polyethylene Glycol 3350 for Constipation in Children With Dysfunctional Elimination

Children with daytime wetting often have constipation, and treatment of constipation helps children become dry. Polyethylene glycol 3350 (Miralax, Braintree Laboratories, Braintree, Massachusetts) is a nonaddictive, tasteless powder that can be mixed with any liquid for treatment of constipation. We review our use of polyethylene glycol 3350 in 35 girls and 11 boys with dysfunctional elimination. Noninvasive urodynamic studies and post-void residual measurement were performed before and during treatment. A significant increase in frequency of bowel movements occurred while taking polyethylene glycol 3350 (p = 0.0001). Average final dose was 0.63 gm/kg. The only reported adverse effect was diarrhea (9 patients). Of the children 18 became dry, 26 had decreased wetting and 2 had no improvement. Voided volume increased (146 vs 210 ml, p <0.0001) and post-void residual decreased significantly (92 vs 48 ml, p <0.0001) while on polyethylene glycol 3350. Ten children were still considered constipated including both patients who experienced no change in wetting. Average final dose in this group (0.69 gm/kg) did not differ significantly from those in whom constipation resolved (0.61 gm/kg). Patients in whom constipation resolved had a significantly lower post-void residual than those who remained constipated (11.8% vs 30.6%, p <0.01) and were significantly more likely to become dry or improved (p = 0.045). The efficacy, compliance and lack of significant side effects make polyethylene glycol 3350 an ideal substance for treatment of constipation in children with dysfunctional elimination. Persistent constipation was associated with decreased resolution of voiding symptoms and significantly increased post-void residuals.

Intracochlear administration of thiourea protects against cisplatin-induced outer hair cell loss in the guinea pig

Amelioration of cisplatin-induced side-effects is of great clinical importance. Local administration of a cytoprotective agent to the inner ear offers a possibility to prevent cisplatin-induced ototoxicity without risk of interference with the antitumour effect. The ideal substance for local administration has yet to be identified. Thiourea (TU) has unique properties that make it an interesting candidate. This study was initiated to test the hypothesis that TU given by local administration protects against cisplatin ototoxicity in the guinea pig. After baseline auditory brainstem response (ABR) assessment, the left cochlea was implanted with a microtip catheter connected to an osmotic pump filled with either 27 mg/ml TU in artificial perilymph (AP), or AP administered for the full duration of the study. Three days post-implant, animals with normal ABRs received an intravenous injection of 8 mg/kg body-weight cisplatin. Five days after the cisplatin treatment ABRs were reassessed, animals decapitated and bilateral cytocochleograms prepared. TU-treated ears demonstrated significantly lower outer hair cell (OHC) loss as compared to contralateral untreated ears, and significantly lower OHC loss compared to AP-treated ears. ABR threshold shift did not differ significantly between the two groups. It can be postulated that TU demonstrates partial protection against cisplatin-induced ototoxicity.