Minimal Breakdown Research Articles

From the quantum breakdown model to the lattice gauge theory

The one-dimensional quantum breakdown model, which features spatially asymmetric fermionic interactions simulating the electrical breakdown phenomenon, exhibits an exponential U(1) symmetry and a variety of dynamical phases including many-body localization and quantum chaos with quantum scar states. We investigate the minimal quantum breakdown model with the minimal number of on-site fermion orbitals required for the interaction and identify a large number of local conserved charges in the model. We then reveal a mapping between the minimal quantum breakdown model in certain charge sectors and a quantum link model which simulates the U(1) lattice gauge theory and show that the local conserved charges map to the gauge symmetry generators. A special charge sector of the model further maps to the PXP model, which shows quantum many-body scars. This mapping unveils the rich dynamics in different Krylov subspaces characterized by different gauge configurations in the quantum breakdown model.

Closure of Giant Dorsal Lumbosacral Myelomeningocele in Children Using Double Expanded Flaps: A Case Report and Literature Review.

Myelomeningocele (MMC) is the most common neural tube defect that can occur due to neural tube's failure to fuse properly during embryonic life. To prevent this, expanded flaps can be used for closure of large MMCs. A 4-year and 6-month girl was diagnosed with multiple congenital anomalies including hydrocephalus, dorsal lumbosacral MMC, and congenital tethered cord syndrome. Preoperative evaluation showed no lower limb movements and the size of the sacrococcygeal region was about 10cm × 8cm × 15cm mass, prominent thoracic kyphosis, and no obvious urogenital or limb anomalies. The large dorsal lumbosacral MMC was treated with a double expanded flap to reconstruct, the soft tissue defect following the neurosurgical reconstruction. The expanded flap was deemed as viable as all wounds were healed without any complications, such as dehiscence, leakage of cerebrospinal fluid, or infection. The technique described in the case report offers an effective method of closure. This flap can be an effective method for reconstruction of large dorsal lumbosacral MMC defects that might improve outcomes and minimize complications. It also ensures minimal wound tension and breakdown.

A Comparison of Emergence Behaviour and Cost Effectiveness in Tonsillectomy Patients Undergoing General Anaesthesia with Desflurane versus Sevoflurane

Background: It has been seen that volatile anaesthetics agents which are speedily eliminated with minimal breakdown should facilitate faster recovery from general anaesthesia. As compared to isoflurane-based anaesthesia, both sevoflurane and desflurane have shorter emergence times due to rapid induction and elimination.
 Aim: The aim of this study is to compare and analyse the superiority of both agents, with regards to the emergence and recovery from anaesthesia, intraoperative hemodynamics, postoperative side effects and estimate the average quantity and cost-benefit of both volatile agents consumed.
 Methods: Total of 100 cases above the age of 6 years undergoing tonsillectomy surgeries of ASA grade 1& 2 was included. Patients were allocated into two groups by computer-generated numbers. Group S: Anaesthesia maintained with 50/50 mixture of nitrous oxide/oxygen and sevoflurane. Group D: Anaesthesia maintained with 50/50 mixture of nitrous oxide/oxygen and desflurane. The parameters recorded were compared between the two groups using the unpaired t-test for continuous variables and P≤0.005 is deemed significant.
 Results: There was no significant hemodynamic difference intraoperatively between sevoflurane and desflurane except in the desflurane group, heart rate was higher. Recovery was faster and better in Group D.
 Conclusion: Postoperative recovery was better and faster and postoperative complication was lower in the desflurane group. Though the total cost of desflurane group was higher compared to sevoflurane but the use of desflurane can be justified with lesser complication, faster emergence from anaesthesia, faster shifting from PACU, lesser hospital stays, lower chance of nosocomial infection and lower cost of hospital stay.

Effect of the cholesterol on electroporation of planar lipid bilayer

Electroporation threshold depends on the membrane composition, with cholesterol being one of its key components already studied in the past, but the results were inconclusive. The aim of our study was to determine behaviour of planar lipid bilayers with varying cholesterol concentrations under electric field. This would give us a better insight into cholesterol effect on membrane properties during electroporation process, since cholesterol is one of the major components of biological membranes and plays a crucial role in membrane organisation, dynamics, and function. Planar lipid bilayers were prepared from phosphatidylcholine lipids with 0, 20, 30, 50 and 80 mol% cholesterol. Capacitance was measured using the discharge method. Results show no statistical difference of cBLM between the cholesterol concentrations. Breakdown voltage Ubr of planar lipid bilayers was measured by means of linear rising voltage with seven different slopes. Obtained results were fitted to a strength-duration curve, where parameter Ubrmin represents minimal breakdown voltage, and parameter τRC represents the inclination of the strength-duration curve. Adding cholesterol to planar lipid bilayer gradually increased its Ubrmin until 50 mol% cholesterol concentration. Afterwards at 80 mol% Ubrmin does not further increase, in fact it reduces by 20% of the Ubrmin at 50 mol% cholesterol concentration.

Pasting Properties of Selected Rice Varieties from Several Provinces in Indonesia

Pasting properties play an important role in determining the quality of cooked rice, or other related food products. These attributes of several rice varieties from North Sumatera, West Sumatera, South Sumatera, Banten, West Java, Central Java, Yogyakarta, East Java, and South Sulawesi were measured, using Brookfield viscometer DV-II+Pro. Popular brands are believed to leverage the potentials, in order to possibly predict customer’s preference. Pasting temperature, peak viscosity, viscosity after 10 minutes at 93.5°C, break down intensity, viscosity at 50°C, and degree of setback, were subsequently evaluated. The extent of breakdown and setback situations were instrumental in characterizing paste stability as well as the retrograde tendency, after cooling. Furthermore, Anak Daro (West Sumatera) demonstrated optimal paste stability, with very minimal breakdown value (231cP). This estimate was significantly lower, compared to most samples, with exception to Ceredek, IR 42 (West Sumatera), Jago Pelung, Pandan Wangi (West Java), Pandan Wangi (East Java), and Memberamo (South Sulawesi). Conversely, Berlian (East Java) showed the greatest retrograde tendency, with maximum setback value (3865 cP). However, the evaluation was more extensively, than other varieties, excluding Ramos Kembang, Ramos Walet (Banten), and C4 (Central Java).

Application of Laser Flare Photometry in the Quantification of Blood–Aqueous Barrier Breakdown after Micro-incision Vitrectomy

ABSTRACTPurpose: The purpose of the study is to quantify aqueous flare using laser flare photometry (LFM) in patients undergoing 25-G pars plana vitrectomy (PPV) and assess the need for postoperative topical corticosteroid administration .Methods: Prospective evaluation of 50 eyes (50 patients) was performed using LFM until day 30 postoperative. Duration of surgery, indication of PPV, and use of laser and/or cryotherapy were noted. Topical corticosteroids were used if mean LFM values were >50, or if there was anterior chamber fibrin.Results: Mean age of the subjects was 48.62 ± 10.07 years. The preoperative LFM value for 50 subjects was 17.42 ± 25.20. Topical corticosteroids were initiated in only 22 patients. The LFM values of subjects were not different from baseline at 1 month whether or not the subjects received corticosteroids (p > 0.106).Conclusions: With 25-G PPV, there is minimal breakdown of blood–aqueous barrier. LFM helps in monitoring postoperative inflammation, obviating the need for topical corticosteroids in significant number of patients.

Comparative Evaluation of Shear Bond Strength and Microleakage of Two Self-adhering Composite Resins: An in vitro Study

A good dental cement used as repair material should possess chemical binding, easy handling characteristics, minimal marginal breakdown and minimal polymerization shrinkage, high resistance to wear, high cohesive strength, and good color stability. This study was undertaken to compare the in vitro microleakage and shear bond strength among the newly introduced Prime fill flow and Dyad flow. The aim of this study was to determine the effect on shear bond strength and microleakage of two self-adhesive composite resin. Selected specimens were collected and stored in deionized water with an antibactericidal agent, 0.2% sodium azide, until ready to be used and were randomly divided into two groups: group I: Dyad flow and group II: Prime fill flow; specimens were sheared with a universal testing machine, and the results were calculated in megapascal, specimens were sectioned in a mesiodistal direction at four different locations, and analyzed for leakage (dye penetration) using a stereomicroscope. The results of the present study showed that acceptable values for Prime fill flow seemed to have least microleakage and high bond strength as compared with Dyad flow. Here, it can be concluded that there was significant difference in the in vitro microleakage and shear bond strength among the Prime fill flow and Dyad flow. Self-etch adhesives when compared with total-etch systems have the advantage of reducing the application time and the number of steps in pediatric dentistry. Patients' age and cooperation are not always ideal; the treatment outcome is greatly influenced by the patients' behavior. It is therefore imperative to recede the application time of some materials mostly in pediatric dentistry.

Subtitling on the Intersection of Theory and Practice: Pedagogical Research-Based Approach to Subtitler Training

The present article investigates our proposed approach for subtitler training namely a Pedagogical Research-Based (PRB), defined as a professionally-oriented approach utilised in Audiovisual Translation (AVT) translator training to theoretically and practically strengthen the subtitling skills of trainees. The data of the present study is derived from an Egyptian television hard-edged drama entitled Firqit Naji Atallah (lit. Naji Atallah Team), Episode 1 (2012), subtitled by a sample of twenty MA translation students, ten of whom enrolled in the second semester for the academic year 2013/2014 and the rest (also totalling ten) did the same, a year later, namely for the school year 2014/2015. The article clearly reveals that before PRB approach is introduced in actual translation classroom, translator trainees (i.e. experimental group) are faced with tremendously difficult problems linguistically, culturally and technically which may hinder communication, thought to be crucial to retain for the target audience. The PRB approach is then introduced whereby the other translator trainees are equipped with some theoretical insights apropos of subtitling norms, well-envisaged in two scholarly AVT works by Karamitroglou (1998) and Schwarz (2002). Being aware of the PRB approach, the translator trainees could therefore do the translation task with minimal linguistic, cultural and technical problems. The study concludes with some pedagogical implications that will hopefully help translator trainees do translation tasks with minimal communication breakdown and maximal communicative thrust drawing on PRB.

Abstract 4242: Rhodamine esters as fluorescent tumor painting agents for glioblastoma

Abstract GBM remains one of the most difficult cancers to treat. Despite surgery, radiation and chemotherapy, tumors invariably recur. There is a strong correlation between extend of resection and subsequent time to recurrence and ultimate patient survival. A key challenge for the neurosurgeon is to minimize removal normal brain tissue whilst being as aggressive as possible with regards of removal of tumor tissue. Defining tumor boundary during surgery remains challenging. Fluorescent dyes such as 5- Aminolevulinic acid, have been studied as aids for tumor delineation but have failed to gain widespread acceptance in clinical practice. It has long been known that a substantial number of cancers, including Glioblastoma, exhibit a hyperpolarization of the plasma and mitochondrial membrane potential. This hyperpolarization is manifest by increased retention of lipophilic cationic dyes (Nernstian probes), such as the SPECT-CT probes 99Tc-Sestamibi and 99Tc-Tetrofosmin in both glioma cells in culture and primary tumors. We synthesized a series of ester derivatives of Rhodamine B with high fluorescence quantum yield in the red spectrum and a very favorable biological safety profile. Utilizing a series of intracranial xenografted glioblastoma pre-clinical mouse models, we show that a single I.V. injection of 1 mg/kg fluoroethylrhodamine ester (RhoFe) results in dramatic selective fluorescence in tumor but not surrounding normal brain tissue. This was observed even in tumors with minimal breakdown of the blood brain barrier, as determined by T1-contrast enhancing agents. RhoFe-tumor-selective fluorescence can remain visible up to 72 hours after injection. Similar results were obtained with Tetramethylrhodamine ester (TMRE) and rhodamine 123 (Rho123), but unlike RhoFe, TMRE proved highly toxic, while Rho123 fluorescence was both weaker and in the green spectrum, accompanied by higher endogenous auto-fluorescence. While well tolerated in vivo, RhoFe shows strong photoxicity in cell culture, suggesting potential as a photodynamic therapy agent. Taken together, these data suggest that RhoFe may be a promising tumor painting agent, with potential utility in fluorescence guided surgery as well as photodynamic therapy. Citation Format: Yu-Hsi Lin, Steven Millward, Seth Gammon, Nikunj Satani, Naima Hammoudi, Joshua Philip Gray, Lindsay E. Kelderhouse, Argentina Ornelas, Haley Schroeder, Florian L. Muller. Rhodamine esters as fluorescent tumor painting agents for glioblastoma. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4242.

Estimation of Minimal Breakdown Point in a GaP Plasma Structure and Discharge Features in Air and Argon Media

We present gas discharge phenomena in argon and air media using a gallium phosphide (GaP) semiconductor and metal electrodes. The system has a large-diameter (D) semiconductor and a microscaled adjustable interelectrode gap (d). Both theoretical and experimental findings are discussed for a direct-current (dc) electric field (E) applied to this structure with parallel-plate geometry. As one of the main parameters, the pressure p takes an adjustable value from 0.26 kPa to 101 kPa. After collection of experimental data, a new theoretical formula is developed to estimate the minimal breakdown point of the system as a function of p and d. It is proven that the minimal breakdown point in the semiconductor and metal electrode system differs dramatically from that in metal and metal electrode systems. In addition, the surface charge density σ and spatial electron distribution n e are calculated theoretically. Current–voltage characteristics (CVCs) demonstrate that there exist certain negative differential resistance (NDR) regions for small interelectrode separations (i.e., d = 50 μm) and low and moderate pressures between 3.7 kPa and 13 kPa in Ar medium. From the difference of currents in CVCs, the bifurcation of the discharge current is clarified for an applied voltage U. Since the current differences in NDRs have various values from 1 μA to 7.24 μA for different pressures, the GaP semiconductor plasma structure can be used in microwave diode systems due to its clear NDR region.

Primary closure of the deltopectoral flap-donor site without skin grafting

Background and objective: Deltopectoral flap is a two staged flap requiring skin graft of the donor site. This study was conducted to evaluate the possibility of primary closure of the deltopectoral flap-donor site without skin grafting. Methods: The operations were conducted at Rizgari Teaching Hospital in the center of Erbil City, Kurdistan Region of Iraq. From January 2009 to December 2012, 14 deltopectoral flaps for reconstruction of oral/facial cancer ablative defects were done. Data on the age, gender, tumor site, and postoperative complications related to primarily closed deltopectoral flap-donor site (fistula, dehiscence, or hematoma leading to impairment of wound healing) and postoperative hospital stay were recorded. Results: Of the 14 head-and-neck tumours, 10 were squamous cell carcinomas and four were ameloblastomas. Eleven of the patients were males and only three were females. The mean age (±SD) of the patients was 59±13 years. There was no evidence of partial or complete loss of the flap in any of the patients studied. There was no case of breakdown of the primarily closed donor site. The only registered complication was slight localized dehiscence at the most proximal and distal part of the primarily sutured flap donor site in one patient. Conclusion: Primary closure of deltopectoral flap donor site is possible with minimal complication that overcomes the problem of skin grafting. Minimal wound breakdown in younger patients had been noted and left to heal by secondary intention.

An organotypic uniaxial strain model using microfluidics

Traumatic brain injuries are the leading cause of disability each year in the US. The most common and devastating consequence is the stretching of axons caused by shear deformation that occurs during rotational acceleration of the brain during injury. The injury effects on axonal molecular and functional events are not fully characterized. We have developed a strain injury model that maintains the three dimensional cell architecture and neuronal networks found in vivo with the ability to visualize individual axons and their response to a mechanical injury. The advantage of this model is that it can apply uniaxial strains to axons that make functional connections between two organotypic slices and injury responses can be observed in real-time and over long term. This uniaxial strain model was designed to be capable of applying an array of mechanical strains at various rates of strain, thus replicating a range of modes of axonal injury. Long term culture, preservation of slice and cell orientation, and slice-slice connection on the device was demonstrated. The device has the ability to strain either individual axons or bundles of axons through the control of microchannel dimensions. The fidelity of the model was verified by observing characteristic responses to various strain injuries which included axonal beading, delayed elastic effects and breakdown in microtubules. Microtubule breakdown was shown to be dependent on the degree of the applied strain field, where maximal breakdown was observed at peak strain and minimal breakdown is observed at low strain. This strain injury model could be a powerful tool in assessing strain injury effects on functional axonal connections.

Calmodulin protects androgen receptor from calpain-mediated breakdown in prostate cancer cells

Although inactivation of the androgen receptor (AR) by androgen-ablation or anti-androgen treatment has been frontline therapy for disseminated prostate cancer for over 60 years, it is not curative because castration-resistant prostate cancer cells retain AR activity. Therefore, curative strategy should include targeted elimination of AR protein. Since AR binds to calmodulin (CaM), and since CaM-binding proteins are targets of calpain (Cpn)-mediated proteolysis, we studied the role of CaM and Cpn in AR breakdown in prostate cancer cells. Whereas the treatment of prostate cancer cells individually with anti-CaM drug or calcimycin, which increases intracellular Ca(++) and activates Cpn, led to minimal AR breakdown, combined treatment led to a precipitous decrease in AR protein levels. This decrease in AR protein occurred without noticeable changes in AR mRNA levels, suggesting an increase in AR protein turnover rather than inhibition of AR mRNA expression. Thus, CaM inactivation seems to sensitize AR to Cpn-mediated breakdown in prostate cancer cells. Consistent with this possibility, purified recombinant human AR (rhAR) underwent proteolysis in the presence of purified Cpn, and the addition of purified CaM to the incubation blocked rhAR proteolysis. Together, these observations demonstrate that AR is a Cpn target and AR-bound CaM plays an important role in protecting AR from Cpn-mediated breakdown in prostate cancer cells. These observations raise an intriguing possibility that anti-CaM drugs in combination with Cpn-activating agents may offer a curative strategy for the treatment of prostate cancer, which relies on AR for growth and survival.

Windows of metamorphic sulfur liberation in the crust: Implications for gold deposit genesis

Abstract Understanding the source of metamorphic sulfur is critical to clarifying the complete cycle of ore genesis, from source to sink, for several mineral deposit types. In this study, a mass balance approach and the thermodynamic computer programs T hermocalc and PerpleX were used to constrain the P-T range of pyrite breakdown to pyrrhotite (which liberates sulfur) in common metamorphic lithologies. The results suggest that most of the continental crust’s metamorphic sulfur is liberated in a relatively narrow temperature–pressure window corresponding to the terminal breakdown of chlorite at moderate to low pressures. This is because pyrite stability is controlled partly by temperature and pressure, and partly by the amount of H2O present. During prograde metamorphism from the greenschist to the amphibolite facies, metamorphic H2O is produced primarily through chlorite breakdown in mafic to pelitic bulk compositions. As temperature increases, more sulfur is required from pyrite to maintain equilibrium proportions of H2O, H2S and SO2 in the fluid, and in addition, progressively more sulfur is required at lower pressures. At low temperatures, little sulfur is required by metamorphic fluid released during initial chlorite breakdown, whereas at higher temperatures coinciding with the terminal breakdown of chlorite, not only is more fluid present, but the fluid’s sulfur requirement has also increased dramatically. In this way, metamorphic dehydration drives pyrite breakdown and generation of sulfur-rich hydrothermal fluids at mesothermal conditions. Beyond the chlorite stability field there is minimal metamorphic fluid production, except at low pressures and high temperatures where muscovite can break down without causing melting; conditions that are a long way from typical crustal geotherms. However, deformation also plays a key role in pyrite breakdown. Without deformation, small amounts of fluid in chemical communication with individual pyrite grains will quickly acquire equilibrium concentrations of the sulfur species and minimal pyrite breakdown is necessary. Whereas during deformation, there may be a continuous fluid flux past pyrite grains, promoting ongoing sulfur liberation. In this way, periods of deformation may be the major sulfur-liberating episodes during a metamorphic cycle. Since hydrothermal fluids are inherently buoyant and consequently tend to migrate upwards and towards cooler temperatures through the crust, these results imply that orogenic gold deposits are most likely to form at lower-amphibolite to prehnite-pumpellyite facies conditions, and unlikely to form at higher temperatures. The pressure constraint on metamorphic sulfur liberation implies that tectonic settings that allow prograde metamorphism to follow low pressure P-T-t paths in an occasionally compressional or transpressional environment are necessary. Settings that promote extensive injection of felsic magma into a mid-crust that contains a significant proportion of pyritic carbonaceous metasediment are shown to be ideal for orogenic gold deposit genesis. Inverted back-arc basins are interpreted to be the most favourable of these.

Determination of the lipid bilayer breakdown voltage by means of linear rising signal

Electroporation is characterized by formation of structural changes within the cell membrane, which are caused by the presence of electrical field. It is believed that “pores” are mostly formed in lipid bilayer structure; if so, planar lipid bilayer represents a suitable model for experimental and theoretical studies of cell membrane electroporation. The breakdown voltage of the lipid bilayer is usually determined by repeatedly applying a rectangular voltage pulse. The amplitude of the voltage pulse is incremented in small steps until the breakdown of the bilayer is obtained. Using such a protocol each bilayer is exposed to a voltage pulse many times and the number of applied voltage pulses is not known in advance. Such a pre-treatment of the lipid bilayer affects its stability and consequently the breakdown voltage of the lipid bilayer. The aim of this study is to examine an alternative approach for determination of the lipid bilayer breakdown voltage by linear rising voltage signal. Different slopes of linear rising signal have been used in our experiments (POPC lipids; folding method for forming in the salt solution of 100 mM KCl). The breakdown voltage depends on the slope of the linear rising signal. Results show that gently sloping voltage signal electroporates the lipid bilayer at a lower voltage then steep voltage signal. Linear rising signal with gentle slope can be considered as having longer pre-treatment of the lipid bilayer; thus, the corresponding breakdown voltage is lower. With decreasing the slope of linear rising signal, minimal breakdown voltage for specific lipid bilayer can be determined. Based on our results, we suggest determination of lipid bilayer breakdown voltage by linear rising signal. Better reproducibility and lower scattering are obtained due to the fact that each bilayer is exposed to electroporation treatment only once. Moreover, minimal breakdown voltage for specific lipid bilayer can be determined.

Pre‐vegetation alluvial fan facies and processes: an example from the Cambro‐Ordovician Rozel Conglomerate Formation, Jersey, Channel Islands

AbstractPrior to the Silurian a lack of land vegetation is expected to have influenced the processes of sedimentation on alluvial fans, principally by causing increased rates of run‐off and erosion in the fan catchments. In the Cambro‐Ordovician Rozel Conglomerate Formation, this effect was central to the generation of alluvial fan deposits that are unusually deficient in sand and clay, despite being sourced from a catchment dominated by sandstone and mudstone. Seven facies are identified, interpreted as representing the deposits of: (i) shallow stream and sheetfloods, (ii) channelized, non‐cohesive debrisflows, (iii) sub‐aerial mud‐rich debrisflows, (iv) sub‐aqueous mud‐rich debrisflows, (v) low energy streams that reworked abandoned fan sectors, (vi) a sandflat‐playa lake system and (vii) talus slopes. The first two facies are both clast‐supported conglomerate, comprise 98% of the deposit, and represent deposition on active depositional lobes and in the fan head trench. The remaining facies are the products of infrequent sedimentary processes, fan abandonment processes and marginal sub‐environments. The facies assemblage in many ways mimics that of a modern‐day, water‐lain, arid region fan. However, the palaeolatitude of these fans was high and the climate is inferred to have been cool and wet. The near absence of sandstone and mudstone beds with few mudflows is ascribed to rapid hinterland uplift and high rates of erosion resulting in minimal chemical breakdown of source rocks in the catchments. Such high rates of erosion are in turn ascribed to a combination of frequent rainstorms and an absence of vegetation cover.

The relationship between dermal pressure ulcers, oxygenation and perfusion in mechanically ventilated patients

More than 1.5 million hospitalized patients develop dermal pressure ulcers (DPUs) annually, which increases cost and prolongs length of stay. Mechanically ventilated patients may be at a high risk for DPU development, but research has not focused on the prevalence of dermal pressure ulcers in this population or the factors associated with dermal pressure ulcer development. To determine the prevalence of dermal pressure ulcers in subjects receiving mechanical ventilation and to describe the relationship between systemic oxygenation, tissue perfusion, and the prevalence of dermal pressure ulcers. Subjects from an Intensive Care Unit in a Midwestern hospital in the United States were recruited into this descriptive, correlational study following intubation. Variables included: demographics, general subject status (weight, serum albumin), ventilatory status, oxygenation status (arterial blood gas analysis including concentration of hydrogen ions, partial pressure of carbon dioxide, partial pressure of oxygen, and amount of oxygen carried by hemoglobin), perfusion status (mean arterial pressure, heart rate, urine output), and skin condition. The Braden Scale was used to measure the risk of skin breakdown, with any skin breakdown being classified in stages ranging from I to IV (I having minimal breakdown, IV having maximal breakdown). Braden Scores range from 6 to 23, with a score of 6 indicating high risk and a score of 23 indicating low risk. Data were collected every other day after admission to the Medical Intensive Care Unit until extubation, transfer, or death. Subjects (n = 40) were primarily Caucasian (77.5%), having a mean age of 56.4 years (+/-14.6 years). Half of the sample was male (50%). Twenty percent of the sample developed DPUs. A Pearson's correlation identified the significant associations between the Braden Score and MAP, PaCO(2), largest weight fluctuation in a 3-day period, and change in weight from admission to discharge. Surprisingly, the lowest Braden Score was not significantly associated with the development of DPUs. Mechanically ventilated patients are vulnerable to developing dermal pressure ulcers as evidence by 20% of the subject population developing a dermal pressure ulcer. The most significant factors related to a low Braden Score in this group are fluid shifts and fluid weight gain. This may be an important predictor of dermal pressure ulcers not currently assessed clinically.

Muscle (pectoralis major) protein turnover in young broiler chickens fed graded levels of lysine and crude protein

An evaluation of muscle (pectoralis major) protein turnover using the phenylalanine flood dose technique was assessed in broiler chicks fed graded dietary lysine levels with CP at 170, 210, 250, and 290 g/kg diet. Chicks at 21 d old were injected with 1 mL/100 g BW of a phenylalanine solution (120 micromol L-[ring-2H5)]-phenylalanine). Muscle protein gain was assessed in chicks at 19 and 23 d of age. No differences were found in weight gain at lysine levels higher than 1.22% of the diet. Dietary lysine levels affected fractional synthesis rate (FSR, %/ d) of muscle with 170 and 210 g of CP/kg diet but not with 250 and 290 g of CP/kg. However, there was increasing FSR with increasing diet lysine levels at 290 g of CP/ kg. Breast muscle protein deposition (absolute growth rate, AGR, mg/d) reached a plateau with 1.22% dietary lysine at CP levels of 170,210, and 290 g/kg diet, confirming the observation on gross muscle weight. In terms of absolute synthesis rate/AGR with minimal absolute breakdown rate (ABR), the diet containing 210 g of CP/kg with 1.22% lysine was the most appropriate for chicks to 21 d. Levels of lysine influenced protein synthesis more so than protein degradation. These data suggest that both protein synthesis and breakdown increase at levels of dietary lysine and CP above those required for maximizing growth.

Surface ultrastructural studies on the germination, penetration and conidial development of Aspergillus flavus Link:Fries infecting silkworm, Bombyx mori Linn.

Aspergillosis is a common disease of the silkworm Bombyx mori Linn., caused by an insect mycopathogen Aspergillus flavus Link:Fries. The present study reveals the germination, penetration and conidial development of A. flavus on the larval integument of B. mori under SEM. Four different strains (NB18, KA, NB4D2 and NB7) of B. mori was surface inoculated with ca. of 1 x 10(6) conidia/ml. Each conidium germinated on the cuticle approximately 6 h after inoculation, forming a humpy or suctorial appressoria within 24 h. The hyphae which entered into haemocoel 2 day post-inoculation, grew and multiplied extensively, forming a mycelial complex, causing death of the host larva in about 4-5 days. This occurred with minimal breakdown of the internal tissues. Death of the host was followed by ramification of the fungus through the mesodermal and epidermal tissues, leading to larval mummification about 5-6 days after inoculation. Extensive fungal growths on the entire larval body followed, consisting of aerial hyphae, which developed branched conidiophores. The aerial hyphae with abundant conidiophores formed a confluent yellowish green fungal mat over the entire larval body in 6-7 days of post-inoculation. The tip of each emerging conidiophores gradually dilated and developed to become a bulbous head known as the vesicle. A large number of conidiogenous cells were produced over the entire surface of vesicle, which later developed into finger-like projections termed as sterigmata or phialides. The phialides matured within 2 days after the aerial hyphae emerged as evidenced by chains of conidia at their tips. The conidia were globose with externally roughened walls. The life cycle of the fungus on B. mori was completed in six to seven days.

Multi-element removal from road-deposited sediments using weak hydrochloric acid

Dilute HCl is a widely applied partial digestion procedure in geo-environmental investigations. Concentrations of HCl from 0.07 to 12 M have been applied to digest solid media, either shaken at room temperature ("cold") or heated to temperatures of 80–95 °C ("hot"). From an exhaustive literature survey, 0.5 M HCl was selected as the most appropriate single leach partial digestion procedure for examining potentially contaminated road-deposited sediments (RDSs). Both cold and hot HCl treatments were examined using objective criteria to identify the leach that produced the most environmentally meaningful data. The treatments were judged according to minimal breakdown of the aluminosilicate lattice and/or liberation of refractory-associated fractions of Al, Cr, and Fe; high recoveries for suspected contaminants (Cu, Pb, and Zn); and contaminant concentrations independent of clay content, organic C content, carbonate content, and cation exchange capacity. Based on all criteria, the cold 0.5 M HCl procedure was identified as superior to the hot HCl treatment. The cold treatment showed limited removal of Al, Cr, and Fe from the residual fraction, with the hot treatment having three- to sevenfold greater removal efficiencies. This suggests significant breakdown of structural lattice and liberation of elements from fractions not generally considered environmentally important. Hot HCl removed quantitative amounts of Cu and Zn from the road sediments, indicating structural release. The greater structural breakdown associated with hot HCl is a major disadvantage for studies examining bioavailability. All data point to the superiority of a cold HCl leach for geo-environmental contaminant studies. Electronic supplementary material to this paper can be obtained by using the Springer LINK server located at http://dx.doi.org/10.1007/s00254-002-0598-8