Continuous Blood Pressure Estimation From Non-Invasive Measurements Using Support Vector Regression.

Blood pressure (BP) is one of the most crucial vital signs of the human body that can be assessed as a critical risk factor for severe health conditions such as cardiovascular diseases (CVD) and hypertension. An accurate, continuous, and cuff-less BP monitoring technique could help clinicians improve the prevention, detection, and diagnosis of hypertension and manage related treatment plans. Notably, the complex and dynamic nature of the cardiovascular system necessitates that any BP monitoring system could benefit from an intelligent technology that can extract and analyze compelling BP features. In this study, a support vector regression (SVR) model was developed to estimate systolic blood pressure (SBP) and diastolic blood pressure (DBP) continuously. We selected a set of features commonly used in previous studies to train the proposed SVR model. A total of 120 patients with available ECG, PPG, DBP and SBP data were chosen from the Medical Information Mart for Intensive Care (MIMIC III) dataset to validate the proposed model. The results showed that the average root mean square error (RMSE) of 2.37 mmHg and 4.18 mmHg were achieved for SBP and DBP, respectively.

Pregnancy and Calving Rates of Cloned Dromedary Camels Produced by Conventional and Handmade Cloning Techniques and In Vitro and In Vivo Matured Oocytes.

Despite practical implication of cloning in camelids, its broad application has been hampered by technical and biological problems. Method of somatic cell nuclear transfer (SCNT) and oocyte competence are the principal technical and biological factors, respectively, that determine the cloning efficiency. This study, therefore, investigated differential contributions of two SCNT methods [modified handmade cloning (mHMC) vs. conventional (cNT)] and two recipient oocyte sources [abattoir-derived (Vitro) vs. FSH-stimulated (Vivo)] on the efficiency of dromedary camel cloning. The mHMC method supported similar rates of fusion, cleavage, and total blastocyst development, compared to conventional NT (cNT) (94, 89.1, and 68.5% vs. 78.9, 92, and 73.5%, respectively) when Vivo oocytes are used. However, using Vitro oocytes, mHMC supported significantly higher rates for these criteria, except for the cleavage, compared to cNT (95.5, 76.2, 25.2% vs. 75.3, 76.7, and 13.9%, respectively). A total of seven clones were born from mHMC/Vitro (four calves), mHMC/Vivo (one calf), cNT/Vitro (one calf), and mHMC/Vivo&Vivo (one calf)-derived embryos with overall efficiencies of 31.9, 26.6, 20, and 30% for initial pregnancy, 10.6, 6.6, 7.5, and 5% for development to term, and 8.5, 6.6, 2.5, 5% for development to weaving, respectively. To conclude, the quality of recipient oocyte greatly impacts cloning efficiency in vitro with no apparent carrying over effect on cloning efficiency in vivo, but the efficiency of SCNT method may compensate for the initial poor oocyte competence during in vitro and in vivo development of cloned embryos. The introduced mHMC could be a superior alternative to conventional method for simple, fast, and efficient production of cloned offspring in camelids.

Heterogeneity in resistant fecal Bacteroides fragilis group collected from healthy people.

Normal nonpathogenic flora would represent a constant lake of resistance genes potentially transferable to human pathogens. To assess the prevalence of resistance genes and genetic variability of Bacteroides fragilis group (BFG) from normal flora, 177 Bacteroides isolates obtained from the fecal samples of healthy individuals. These isolates were subjected to antibiotic susceptibility testing and pulsed field gel electrophoresis (PFGE). The isolates were further tested for the presence of ermF, tetQ and bft genes by PCR. Our results indicated the presence of different clonal strains (1 common type and 57 single types) among the resistant isolates. The resistance rate for the six antibiotics in this study was between 1% and 95%. Most of the isolates (99%) were susceptible to metronidazole. ermF and tetQ were detected in all erythromycin and tetracycline resistant isolates. None of the isolates were carried bft gene. These data suggest dissemination of heterogenic clonal groups in healthy persons and resistance to 5 high commonly used antibiotics.

Nanomechanical actuation of a silicon cantilever using an azo dye, self-assembled monolayer.

The emerging fields of nanomotors and optomechanics are based on the harnessing of light to generate force. However, our ability to detect small surface stresses is limited by temperature drift, environmental noise, and low-frequency flicker electronic noise. To address these limitations, we functionalized microfabricated silicon cantilevers with an azo dye, silane-based self-assembled monolayer and modulated the surface stress by exciting the optical switch with a 405-nm laser. Atomic force microscopy, contact angle analysis, ellipsometry, and X-ray photoelectron spectroscopy verified successful assembly of molecules on the cantilever. Ultraviolet and visible spectra demonstrate optical switching of the synthesized molecule in solution. By turning the laser on and off at a specific rate (e.g., 1 Hz), the cantilever deflection can be measured via Fourier techniques, thus separating the signal of interest from the noise. This technique empowers the design of highly sensitive surface stress measurements.

Amputation-sparing treatment by nature: "surgical" maggots revisited.

Maggots were used as adjunct treatment for infected wounds that showed no response to the classical approach of wound debridement and antibiotic therapy. We summarize findings for 11 patients with necrotic wounds who received treatment with "surgical" maggots (100-2900 applied in 3-10 changes of dressing) for 11-34 days, which apparently aided in tissue remodeling and cure, and describe 2 typical patients in detail.

Hypokalaemia and hyperkalaemia.

Disturbances in potassium homoeostasis presenting as low or high serum potassium are common, especially among hospitalised patients. Given the fact that untreated hypokalaemia or hyperkalaemia is associated with high morbidity and mortality, it is critical to recognise and treat these disorders promptly. In this article, normal potassium homoeostasis is reviewed initially and then a pathophysiological approach to work-up and management of hypokalaemia and hyperkalaemia is presented. Recent advances with respect to the role of kidney in handling of the potassium, the regulation of renal ion transporters in hypokalaemia, and treatment of hypokalaemia and hyperkalaemia will be discussed.

Underuse of primary Mycobacterium avium complex and Pneumocystis carinii prophylaxis in the United States.

BACKGROUND: Little is known about the rates of Mycobacterium avium complex (MAC) and Pneumocystis carinii (PCP) prophylaxis adherence to guidelines and how they have changed after introduction of effective antiretroviral therapy. OBJECTIVE: To determine rates of primary prophylaxis for MAC and PCP and to evaluate the influence of sociodemographic characteristics, region, and provider experience. DESIGN: National probability sample cohort of HIV patients in care. SETTING: One hundred sixty HIV health care providers. PATIENTS: A total of 2864 patients interviewed in 1996 to 1997 (68% response) and 2267 follow-up interviews, representing 65% of surviving sampled patients (median follow-up, 15.1 months). MEASUREMENTS: Use of prophylactic drugs, most recent CD4 count, sociodemographics, and regional and total HIV patients/providers. RESULTS: Of patients eligible for primary MAC prophylaxis (most recent CD4 count <50/mm(3) ), 41% at baseline and 40% at follow-up patients were treated. Of patients eligible for primary PCP prophylaxis (i.e., those with CD4 counts <200/mm(3) ), 64% and 72% were treated, respectively. MAC prophylaxis at baseline was less likely in African American (adjusted odds ratio [OR], 35; 95% confidence interval [CI], 0.20-0.59), Hispanic (OR, 27; 95% CI, 0.08-0.94) and less-educated (OR, 0.61; 95% CI, 0.36-1.0) patients and more likely in U. S. geographic regions in the Pacific West (OR, 4.9; 95% CI, 1.0-23) and Midwest (OR, 6.4; 95% CI, 1.2-33) and in practices with more HIV patients. CONCLUSIONS: Most eligible patients did not receive MAC prophylaxis; PCP prophylaxis rates were better but still suboptimal. Our results support outreach efforts to African Americans, Hispanics, the less educated, and those in the northeastern United States and in practices with fewer HIV patients.

The care of HIV-infected adults in rural areas of the United States.

OBJECTIVE: This study describes the population of HIV-infected adults receiving care in rural areas of the United States and compares HIV care received in rural and urban areas. METHODS: Interviews were conducted with a nationally representative sample of 367 HIV-infected adults receiving health care in rural areas and 2806 HIV-infected adults receiving health care in urban areas of the contiguous United States. RESULTS: We estimate that 4800 HIV-infected persons received medical care in rural areas during the first half of 1996. Patients in rural HIV care were more likely than patients in urban HIV care to receive care from providers seeing few (<10) HIV-infected patients (38% vs. 3%; p <.001). Rural care patients were less likely than urban care patients to have taken highly active antiretroviral agents (57% vs. 73%; p <.001) or Pneumocystis carinii pneumonia prophylactic medication when indicated (60% vs. 75%; p =.006). CONCLUSIONS: Few American adults received HIV care in rural areas of the United States. Our findings suggest ongoing disparities between urban and rural areas in access to high-quality HIV care.

Three-dimensional forced Burgers turbulence supplemented with a continuity equation.

We investigate turbulent limit of the forced Burgers equation supplemented with a continuity equation in three dimensions. The scaling exponent of the conditional two-point correlation function of density, i.e., approximately /x1-x2/(-alpha3), is calculated self-consistently in the nonuniversal region from which we obtain alpha3=3. Also we derive an equation governing the evolution of the probability density function (PDF) of longitudinal velocity increments in length scale, from which a possible mechanism for the dependence of the inertial PDF to one-point u(rms) is developed.

Chronic renal failure in Iranian children.

We investigated chronic renal failure (CRF) in 166 Iranian children (95 boys and 71 girls) from July 1991 to June 1999. The mean age at onset of CRF was 7.9+/-4.5 years. The most common cause of CRF was congenital urological malformations (78 cases). The second most common cause of CRF was hereditary nephropathy (21%). Glomerular diseases accounted for only 10% of children who later went on to develop renal failure. High rates of cystinosis and primary hyperoxaluria were seen, and these elevated rates could be due to a high prevalence of parental consanguinity. Eighty-six patients required renal replacement therapy, of whom the majority underwent hemodialysis. The prevalence of primary reflux as a cause of CRF was high compared with reports from western countries. Earlier diagnosis and management of urinary tract infections in this group could reduce the prevalence of reflux as a cause of CRF in this population.

Expenditures for the care of HIV-infected patients in the era of highly active antiretroviral therapy.

BACKGROUND: The introduction of expensive but very effective antiviral medications has led to questions about the effects on the total use of resources for the care of patients with human immunodeficiency virus (HIV) infection. We examined expenditures for the care of HIV-infected patients since the introduction of highly active antiretroviral therapy. METHODS: We interviewed a random sample of 2864 patients who were representative of all American adults receiving care for HIV infection in early 1996, and followed them for up to 36 months. We estimated the average expenditure per patient per month on the basis of self-reported information about care received. RESULTS: The mean expenditure was $1,792 per patient per month at base line, but it declined to $1,359 for survivors in 1997, since the increases in pharmaceutical expenditures were smaller than the reductions in hospital costs. Use of highly active antiretroviral therapy was independently associated with a reduction in expenditures. After adjustments for the interview date, clinical status, and deaths, the estimated annual expenditure declined from $20,300 per patient in 1996 to $18,300 in 1998. Expenditures among subgroups of patients varied by a factor of as much as three. Pharmaceutical costs were lowest and hospital costs highest among underserved groups, including blacks, women, and patients without private insurance. CONCLUSIONS: The total cost of care for adults with HIV infection has declined since the introduction of highly active antiretroviral therapy. Expenditures have increased for medications but have declined for other services. However, there are large variations in expenditures across subgroups of patients.

Lifshitz point in the phase diagram of a ferroelectric liquid crystal in an external magnetic field

The Lifshitz point in the (H,T) phase diagram of a ferroelectric liquid crystal in a transverse magnetic field has been determined using photon correlation spectroscopy and linear electrooptic response measurements. The extrapolated Lifshitz magnetic field is 25(1+/-0.1) T for a smectic-C* material with an unperturbed helical period of approximately 6 &mgr;m, and the Lifshitz point is located approximately 100 mK above the zero-field transition temperature. We have observed the reentrant helical modulated smectic-C* phase just below the lambda line. The width of this phase is 100 mK at the low temperature critical field H(c) and decreases continuously to zero as we approach the Lifshitz point. The phase boundary between the reentrant phase and the smectic-A phase is of second order, whereas the phase boundary with the unwound smectic-&Cmacr;(*) phase is of first order far away from the Lifshitz point and becomes of second order close to the Lifshitz point. The order parameter dynamics is discussed within the Landau theory.

Alignment of liquid crystals on a photosensitive substrate studied by surface optical second-harmonic generation

The adsorption kinetics and orientational ordering of 4(')-n-octyl-4-cyanobiphenyl (8CB) liquid crystal films evaporated onto photosensitive poly(vinyl-cinnamate) (PVCN) substrates were investigated by surface optical second-harmonic generation. The adsorption rate of the first monolayer decreases with increasing degree of photochemical modification of the polymer. The in-plane orientational anisotropy of the 8CB films grown on unidirectionally photopolymerized PVCN substrates is considerably lower than the intrinsic surface orientational anisotropy of these substrates, which can explain the generally found weak surface anchoring of liquid crystals on PVCN alignment layers.

Lactic acidosis in the setting of antiretroviral therapy for the acquired immunodeficiency syndrome. A case report and review of the literature.

Type B lactic acidosis, a rare but often fatal disorder, has been reported in 21 AIDS patients on antiretroviral therapy (ART). We present an AIDS patient with severe and prolonged lactic acidosis on stavudine and lamivudine. The lactic acidosis occurred in the absence of mitochondrial myopathy, hepatomegaly, or liver failure. This is the second report of lactic acidosis in a patient on stavudine and lamivudine. This patient recovered after aggressive supportive therapy including intravenous alkali and fluid administration as well as continuous venovenous hemodiafiltration. A single dose of dichloroacetate (DCA) was associated with a decrease in the serum lactate level by 20%, which persisted for more than 24 h. Seventeen months after recovery, the patient was rechallenged with ART without recurrence of lactic acidosis. We review and summarize all reported cases of patients with ART-associated lactic acidosis reported in the English literature.

Characterization of unidirectional photopolymerization in poly(vinyl cinnamate) by surface optical second-harmonic generation.

Surface optical second-harmonic generation measurements were used to determine the change in the surface density and the surface orientational order parameter of the trans-cinnamoyl side groups of unidirectionally photopolymerized poly(vinyl cinnamate) (PVCN) films. The observed surface features were compared to the bulk properties of the films, which were probed by their UV absorption spectra and birefringence measurements. We found that the surface and the bulk photoreaction kinetics of the trans cinnamoyl side groups of the PVCN are very similar. The two photoreaction processes (trans-cis photoisomerization and photo-induced cross linking) appear to affect the linear and nonlinear optical properties of the polymer differently. This may explain the discrepancy between the birefringence and the azimuthal anchoring force of the unidirectionally photopolymerized PVCN.

Slow mode of the smectic-A-smectic-C(*)(alpha) phase transition.

Unusual slow fluctuations as revealed recently by dynamic light scattering close to the Sm-A-Sm-C(alpha)(*) phase transition in the antiferroelectric liquid crystal 4-(1-methylheptyloxy-carbonyl)phenyl 4(')-octyloxy biphenyl-4-carboxylate can be explained by the electrostatic coupling between impurity ions and director fluctuations. Within the vicinity of Sm-A-Sm-C(alpha)(*) transition, the relaxation rate of the slow mode depends linearly on temperature, but with a different slope in each phase. The square root of its intensity shows a clear Curie-Weiss divergence at the phase transition, which is a direct confirmation of the electrostatic coupling mechanism.

Suggested guidelines for treatment of acute renal failure in earthquake victims.

The 1990 Iran earthquake affected two states with a combined population of 2,300,000. It resulted in at least 13,888 deaths, 43,390 injured, and 33,616 hospitalized. The overall mortality among hospitalized patients was 0.17%. Acute renal failure (ARF) requiring dialysis support was diagnosed in 156 patients nationwide, with a mortality rate of 14%. Three teaching hospitals of Tehran University of Medical Sciences (UMS) admitted 495 patients, with total mortality of 7.5%. Of these, 30 patients (6%) required dialysis, with a mortality of 40%, accounting for 12 of the deaths. On admission, patients with ARF were more severely injured and had significantly higher incidence of multiple trauma; peripheral nerve injury; elevated muscle enzymes, potassium, and phosphorus; and abnormal urinalysis. In one of these hospitals, patients were treated with a specific hydration protocol coupled with a cautious approach to fasciotomy. The incidence of ARF, mortality associated with ARF, and fasciotomy were lower in this group. Based on these findings, guidelines are suggested that may be helpful in the treatment of ARF in earthquake victims.