Strecker Degradation of a-Amino Acids with B-Phenyl- a, B -dioxopropionanilide

A century ago Strecker observed that alloxan reacts with alanin e to give carbon dioxide and acetaldehyde. 1 A number of c arbonyl compounds have since been found which degrade o:-amino acids to the corresponding aldehyde or ketone with one less carbon atom. A reaction has been carried out by treating the amino acid with the carbonyl compound in aqu eous solu t ion or in suspension

Precision and uncertainties in mass scale predictions in SUSY SO(10) with SU(2)_L x SU(2)_R x U(1)_{B-L} x SU(3)_C intermediate breaking

In a class of SUSY SO(10) with $SU(2)_L x SU(2)_R x U(1)_{B-L} x SU(3)_C$ $(g_{2L}\neq g_{2R})$ intermediate gauge symmetry, we observe that the prediction on the unification mass $(M_U)$ is unaffected by Planck-scale-induced gravitational and intermediate-scale-threshold effects, although the intermediate scale $(M_I)$ itself is subject to such corrections. In particular, without invoking the presence of additional lighter scalar degrees of freedom but including plausible and reasonable threshold effects, we find that interesting solutions for neutrino physics corresponding to $M_I\simeq 10^{10}-10^{13}$ GeV and $M_U\simeq (5-6) x 10^{17}$ GeV are permitted in the minimal models. Possibilities of low-mass right-handed gauge bosons corresponding to $M_I\simeq 1-10$ TeV consistent with the CERN-LEP data are pointed out in a number of models when threshold effects are included using effective mass parameters.Comment: 12 pages including 7 tables (Typos corrected as per the published version

Behaviour of Cyclically Loaded Model Piles in Soft Clay

Instability studies on offshore piles has been carried out to a very limited extent. Cyclic loading resulting from wave action is a very common phenomenon for such piles. Continuous cycling {both vertical and lateral) presumably leads to substantial degradation in pile-soil response, the ultimate result of which could be disastrous. Over the last decade and a half, some work has been done to study the pile-soil interaction behaviour under repeated cyclic loading. This paper aims to highlight and discuss the salient features and the important observations of extensive model tests on piles subjected to vertical cyclic load. The degradation of pile-soil behaviour with different parameters have been studied, rationally analysed and a set of definite conclusions drawn therefrom

Thiol-disulfide Interchange in Formation of β-Lactoglobulin-κ-Casein Complex

n/

WHICH DNA DAMAGE IS LIKELY TO BE RELEVANT IN HORMETIC RESPONSES?

Working under the assumption that hormesis is triggered by specific types of DNA damage, this report focuses on the types of damage which form the signature of ionizing radiation. The key attribute of the signature is the clustering of damage, arising from clusters of energy deposition such that more than one site within a 10 base pair segment of DNA has been chemically altered. A brief overview is given on what is currently believed to be the primary components of clustered damage produced by the direct effect. The overview draws primarily on studies that utilize electron paramagnetic resonance to measure free radical intermediates and gel electrophoresis to measure clustered damage in plasmid DNA. Based on this information, the threshold for a radiation induced biological response is calculated

Impairments in Cerebral Autoregulation is Associated with Postural Control in Sports Related Concussion

Global and regional deficits in cerebral blood flow are reported with concussions, a major public health concern, with approximately 3.8 million incidences occurring annually in the United States alone. Recent studies have identified an increased risk of musculoskeletal injuries in athletes upon return-to-play. Complexity index is a sensitive marker of postural control, with low complexity index indicating a poor physiological adaptation to stress. PURPOSE: Twofold; 1. Examine complexity index and dynamic cerebral autoregulation (dCA) at rest and during physical stress (rhythmic squatting) in collegiate athletes following a concussion in comparison to non-injured controls. 2. Examine the association between complexity index and dCA. METHODS: Athletes (20±1 years) with sports-related concussions were tested on days 3 (N=33), 21 (N=29), and 90 (N=21) following the injury. Controls (N=27) were assessed at one time-point. Continuous mean arterial pressure (MAP) (finger photoplethysmography) and middle cerebral artery blood flow velocity (MCAV) (2 MHz transcranial Doppler ultrasonography) were obtained at rest for 6 minutes and during physical stress (squatting at 0.1Hz frequency) for 5 minutes. Transfer function analysis of beat-to-beat MAP and MCAV oscillations in the low frequency (LF, 0.07-0.20 Hz) range was utilized to assess dCA. Effective dCA dampens the fluctuations in MCAV in response to MAP oscillations, resulting in a low LF gain. Multiscale entropy analysis was used to determine complexity index from the center of pressure data obtained during quiet standing with eyes closed on a force platform. Two-sample Mann Whitney U test was used to compare data between control and concussed athletes at the three time points. Spearman correlation was used to examine the association between the variables. RESULTS: LF gain at rest was higher on day-3 (1.27±0.4U; p=0.007), and day-21 (1.27±0.5U; p=0.03) compared to the controls (1.03±0.2U). Similar findings were observed in LF gain with physical stress (day-3 p= 0.003; day-21 p=0.001). Postural complexity index was lower on day-3 (4.3±1.3U; p=0.004) and day-21 (4.5±1.1U; p=0.02) compared to the controls (5.4±1.4U). Moreover, a negative association was observed between complexity index and LF gain at rest (β= -0.66, p= 0.04) and during squatting (β= -1.53, p= 0.02). CONCLUSION: The findings confirm impairments in cerebral autoregulation and postural control during the acute and subacute recovery phases following a concussion despite symptom resolution. In addition, poor functional outcome, such as postural control, may be associated with alterations in cerebral blood flow regulation in this population. Tracking cerebral autoregulation during recovery phase may help in preventing musculoskeletal injuries in athletes after return-to-play following a concussion

Effects of different ACE inhibitor combinations on albuminuria: results of the GUARD study

Clinical practice guidelines recommend blockers of the renin-angiotensin system alone or in combination with other agents to reduce blood pressure and albuminuria in patients with type 2 diabetes. Dihydropyridine calcium channel blockers, however, may lower blood pressure but not albuminuria in these patients. Here we tested the hypothesis that combining an ACE inhibitor with either a thiazide diuretic or a calcium channel blocker will cause similar reductions in blood pressure and albuminuria in hypertensive type 2 diabetics. We conducted a double blind randomized controlled trial on 332 hypertensive, albuminuric type 2 diabetic patients treated with benazepril with either amlodipine or hydrochlorothiazide for 1 year. The trial employed a non-inferiority design. Both combinations significantly reduced the urinary albumin to creatinine ratio and sitting blood pressure of the entire cohort. The percentage of patients progressing to overt proteinuria was similar for both groups. When we examined patients who had only microalbuminuria and hypertension we found that a larger percentage of the diuretic and ACE inhibitor normalized their albuminuria. We conclude that initial treatment using benzaepril with a diuretic resulted in a greater reduction in albuminuria compared to the group of ACE inhibitor and calcium channel blocker. In contrast, blood pressure reduction, particularly the diastolic component, favored the combination with amilodipine. The dissociation between reductions in blood pressure and albuminuria may be related to factors other than blood pressure

King-Devick Test Score is Linked to Cerebral Vasoreactivity During Acute Recovery Phase Post-Concussion

The King-Devick (KD) test is a quick screening tool used to detect oculomotor and attention related brain function impairments following a concussion. Adequate cerebral blood flow (CBF) is an indicator of structural and functional integrity and impairments in CBF have been linked to cognitive deficits following concussion. Cerebral vasoreactivity (CVR), a key measure of hemodynamic reserve, is an important factor in CBFregulation. PURPOSE: To examine the association between CVR and oculomotor and attention function, using KD test scores, in collegiate athletes following a concussion. METHOD: Eighteen male and female athletes diagnosed with a sports-related concussion were enrolled in the prospective cohort study. Twenty-two non-injured athletes were enrolled as controls. Data was collected longitudinally on day-3, day-21, and day-90 following a concussion. Middle cerebral artery blood velocity (MCAV) was obtained using transcranial Doppler ultrasonography (TCD). CO2 was used as a stimulus to assess CVR. End-tidal CO2 (EtCO2) was monitored with an infrared CO2 analyzer attached to a nasal cannula. Continuous MCAV was obtained for 2-minutes each in response to three CO2 stimuli; normal room-air (normocapnia), inspiring 8% CO2 and 21% O2 gas mixture (hypercapnia), and during hyperventilation (hypocapnia). MCAV and EtCO2 data were plotted and CVR was estimated as the slope of the MCAV and EtCO2 relationship. For the KD test, subjects read aloud single-digit-numbers left to right from three test cards with progressive level of difficulty. Subjects were instructed to read as fast as possible without making errors. KD test score was determined as the sum of the total time required to complete the three test cards. Nonparametric Wilcoxon test was used to assess CVR and KD test scores between control and the concussed group at each of the three time points. Spearman rank order correlation was used to assess the association between CVR and KD scores at each time point. RESULTS: Compared to the control, CVR (1.33±0.31vs.1.14±0.43U; p=0.03) was blunted and KD score (44.4±7.7vs.48.1±6.9sec; p=0.04) was slower on day-3. CVR was comparable to the controls on days 21 and 90. However, a learning effect was observed in KD test score over time (42.1±8.9, p=0.02 [day-21]; 42.03±8.5, p=0.03 [day90]). In addition, a negative correlation between CVR and KD test was observed on day-3 (p= 0.04). CONCLUSION: The preliminary results indicate that deficits in oculomotor function and attention, as identified by KD test, may result from inadequate CBF regulation during the acute recovery phase post-concussion. Further studies should be done to evaluate the potential role of CVR in oculomotor function following concussion in collegiate athletes

Baroreflex Sensitivity is Impaired in Athletes Following a Sports-Related Concussion

Sport-related concussions are a major public health concern, with approximately 3.8 million incidences occurring annually in the United States alone. Autonomic nervous system (ANS) dysfunction is implicated in early and later stages of sports-related concussion recovery. Arterial baroreflex, a crucial mechanism by which the ANS controls short-term fluctuations in blood pressure, remains understudied in this population. PURPOSE: Examine baroreflex sensitivity (BRS) at rest during acute and sub-acute recovery phases following a sport-related concussion in collegiate athletes in comparison to non-injured athletes as controls. METHODS: Athletes (20±1 years) with sports-related concussions were tested on days 3 (N=13), 21 (N=13), and 90 (N=11) following the injury. Control athletes (N=12) were assessed at one time-point. Continuous arterial blood pressure (finger photoplethysmography) and R-R intervals (3-lead electrocardiogram) were obtained at rest for 6 minutes and while subjects were seated in an upright position. BRS was estimated with transfer function analysis to assess the fluctuations in systolic blood pressure and R-R intervals during the time period. Transfer gain in the low-frequency range (0.05– 0.15 Hz) quantified the magnitude of the relationship between changes in systolic blood pressure and R-R interval. Therefore, higher gain indicates higher BRS. A linear mixed model was used to examine symptoms and transfer function variables between the controls and the concussed athletes at the three time points. RESULTS: As anticipated, symptoms were worse on day-3 and resolved during the day-21 sub-acute phase. BRS was lower on day-3 (0.656±0.2U; p=0.003), day-21 (0.711±0.29U; p=0.013), and day-90 (0.77±0.27; p=0.04) following the injury compared to the controls (1.05±0.3U). CONCLUSION: The findings confirm impairments in baroreflex sensitivity during the acute and subacute recovery phases following a concussion despite symptom resolution. Blunted baroreflex sensitivity following injury may position athletes in a vulnerable situation while performing tasks that elicit sudden changes in blood pressure on and off the field

Tensor-network method to simulate strongly interacting quantum thermal machines

We present a methodology to simulate the quantum thermodynamics of thermal machines which are built from an interacting working medium in contact with fermionic reservoirs at fixed temperature and chemical potential. Our method works at finite temperature, beyond linear response and weak system-reservoir coupling, and allows for non-quadratic interactions in the working medium. The method uses mesoscopic reservoirs, continuously damped towards thermal equilibrium, in order to represent continuum baths and a novel tensor network algorithm to simulate the steady-state thermodynamics. Using the example of a quantum-dot heat engine, we demonstrate that our technique replicates the well known Landauer-B\"uttiker theory for efficiency and power. We then go beyond the quadratic limit to demonstrate the capability of our method by simulating a three-site machine with non-quadratic interactions. Remarkably, we find that such interactions lead to power enhancement, without being detrimental to the efficiency. Furthermore, we demonstrate the capability of our method to tackle complex many-body systems by extracting the super-diffusive exponent for high-temperature transport in the isotropic Heisenberg model. Finally, we discuss transport in the gapless phase of the anisotropic Heisenberg model at finite temperature and its connection to charge conjugation-parity, going beyond the predictions of single-site boundary driving configurations.Comment: 21 figures, 25 pages. Updated results, content and references. Journal version (Feature in APS Physics