Effects of postoperative atrial fibrillation on cardiac surgery outcomes in Vietnam: a prospective multicenter study.

BACKGROUND: This study was designed to assess the impact of postoperative atrial fibrillation (POAF) on short- and long-term outcomes after cardiac surgery. METHODS: We prospectively assessed POAF concerning outcomes in 379 adult patients who had undergone cardiac surgery in two heart surgery centers with a follow-up period of one year for every patient. The effects of POAF on postoperative events were evaluated using Logistic regression, Cox regression (adjusted for propensity score), and Kaplan-Meier analysis. RESULTS: The incidence of POAF was 27.2%. Multivariable logistic regression analysis revealed POAF was associated with an increased risk of 6-month (OR = 5.36; CI: 1.51-18.94; p = 0.009), and 1-year mortality (OR = 4.56; CI: 1.29-16.04; p = 0.018) as well as Major Adverse Cardiocerebral Events (MACEs; acute MI, cardiac arrest, low cardiac output after surgery, third-degree atrioventricular block or stroke; OR = 3.02; CI: 1.29-7.05; p = 0.011), Intensive Care Unit (ICU) stay > 3 days (OR = 2.39; CI: 1.14-5.00; p = 0.021), and postoperative stay > 14 days (OR = 3.12; CI: 1.65-5.90; p < 0.001). Multivariable Cox regression analysis showed POAF as an independent predictor of mortality at one year (HR = 2.86; CI: 1.05-7.75; p = 0.038). Discharge plans including statin and beta-blocker had an independent association with a reduced mortality at one year (HR = 0.22; CI: 0.05-0.96; p = 0.045; HR = 0.16; CI: 0.03-0.87; p = 0.034, respectively). CONCLUSIONS: POAF is associated with an increased risk of morbidity, all-cause mortality, and hospital duration. Statins and beta-blockers that were included in discharge plans had an independent association with reduction in 1-year all-cause mortality.

Environmentally-Friendly Pesticidal Activities of Callicarpa and Karomia Essential Oils from Vietnam and Their Microemulsions.

There is an ongoing interest to identify alternative pesticidal agents to avoid the chronic problems associated with synthetic pesticides. Essential oils have shown promise as botanical pest control agents. In the present study, the essential oils of four members of the Lamiaceae (Callicarpa candicans, C. erioclona, C. macrophylla, and Karomia fragrans; Vietnamese names: Nàng nàng, Tu châu lông mem, Tu châu lá to and Cà dien, respectively), obtained from wild populations in Vietnam, have been obtained by hydrodistillation and analyzed by gas chromatography-mass spectrometry. The essential oils were formulated into microemulsions and the essential oils and their microemulsions were screened for mosquito larvicidal activity against Aedes aegypti, Aedes albopictus, Culex quinquefasciatus, and for molluscicidal activity against Pomacea canaliculata. Atractylone and (E)-caryophyllene dominated the volatiles of C. candicans (CCEO) and C. erioclona (CEEO), while the major component in C. macrophylla (CMEO) and K. fragrans (KFEO) was (E)-caryophyllene. The essential oils and microemulsions of both C. candicans and C. erioclona exhibited excellent larvicidal activity against all three mosquito species (Ae. aegypti, Ae. albopictus, and Cx. quinquefasciatus) with LC50 values <10 µg/mL. Additionally, the larvicidal activity of the microemulsions were significantly improved compared with their free essential oils, especially for C. candicans and C. erioclona. All four essential oils and their microemulsions showed excellent molluscicidal activity with LC50 <10 µg/mL. In most cases, the essential oils and microemulsions showed greater pesticidal activity against target organisms than the non-target freshwater fish, Oreochromis niloticus. The in silico studies on physicochemical and ADMET properties of the major components in the studied essential oils were also investigated and most of the compounds possessed a favorable ADMET profile. Computational modeling studies of the studied compounds demonstrated a favorable binding interaction with the mosquito odorant-binding protein target and support atractylone, ß-selinene, and caryophyllene oxide as potential inhibitors. Based on the observed pesticidal activities of the essential oils and their microemulsions, the Callicarpa species and K. fragrans should be considered for potential cultivation and further exploration as botanical pesticidal agents.

Burden and mortality of sepsis and septic shock at a high-volume, single-center in Vietnam: a retrospective study.

BACKGROUND: Sepsis and septic shock have high mortality rates and often require a prolonged hospital stay. Patient outcomes may vary according to multiple factors. We aim to determine the prevalence of antimicrobial resistance and factors associated with mortality and hospital stay. METHODS: Clinical and microbiological data of patients with sepsis or septic shock were retrospectively collected for 15 months. Patients with negative blood cultures and patients that did not meet the SEPSIS 3 criteria were excluded. RESULTS: We included 48 septic shock and 28 septic patients (mean APACHE II 20.32 ± 5.61 and mean SOFA 9.41 ± 3.17), with a mean age of 60.5 ± 16.8 years and 56.6% males. WBCs, neutrophils, INR, and fibrinogen levels were significantly associated with mortality. 59.5% of the cultured bacteria were gram-negative (most common E. coli) and 27.8% were gram-positive (most common S. aureus), while 7.6% were other types of bacteria and 5.1% were fungi. Resistance patterns to gram-negative were varying, and resistance to piperacillin/tazobactam, carbapenems, and aminoglycosides were from 60% to 100% (A. baumanii), while they were highly sensitive to Colistin. E. coli was also resistant to ceftriaxone (77.8%) and sulbactam/cefoperazone (44.4%). Resistance rates for Gram-positives were high, from 86% to 100% for oxacillin, while for vancomycin, teicoplanin, and linezolid, they were often low but arrived up to 42.8%. According to our logistic regression analysis, patients over 65 year-old and those who received corticosteroids had a significantly increased risk of in-hospital mortality (OR: 4.0; OR: 4.8). CONCLUSION: Sepsis still poses a significant threat to patients' health, even when positive blood culture results allow the administration of specific antibiotic treatment.

Predicting atrial fibrillation after cardiac surgery using a simplified risk index.

BACKGROUND: Postoperative atrial fibrillation (POAF) is a common complication after cardiac surgery and can lead to increased risk of postoperative adverse events. However, atrial fibrillation and postoperative adverse events are preventable. In this study, a risk index was developed to predict atrial fibrillation after cardiac surgery. METHODS: A prospective cohort study of 405 patients who had undergone adult cardiac surgery from 2015 September to 2016 August at Heart Institute of HCMC and Cho Ray Hospital were obtained. In order to predict POAF, a logistic regression model was developed, and a risk score was derived and validated by bootstrap. RESULTS: In our study, 98 patients developed POAF (24.2%). The risk score included three significant risk factors (age ≥ 60, left atrial diameter > 41 mm, Coronary Artery Bypass Graft with concomitant mitral valve replacement or repair) that were consistent with other reports. Each of these risk factors was assigned one point. The total risk score ranges from 0 to 3 (AUC = 0.69, 95% CI: 0.63-0.75) with the best cutoff point at 1. According to this scoring system, the incidences of POAF in patients associated with each score of 0, 1, 2, and 3 were 8.6%, 30.1%, 40.8%, and 58.3% respectively. Bootstrapping with 5000 samples confirmed the final model provided was consistent with predictions. CONCLUSIONS: We developed and validated a simple risk score based on clinical variables that can be obtained before surgery in order to accurately predict the risk of POAF in patients undergoing cardiac surgery.

In Situ TEM Studies of Nanostructured Thermoelectric Materials: An Application to Mg-Doped Zn4 Sb3 Alloy.

We demonstrate an advanced approach using state of the art in situ transmission electron microscopy (TEM) to understand the interplay between nanostructures and thermoelectric (TE) properties of high-performance Mg-doped Zn4 Sb3 TE systems. By using the technique, microstructure and crystal evolutions of TE material have been dynamically captured as a function of temperature from 300 K to 573 K. On heating, we have clearly observed precipitation and growth of a Zn-rich secondary phase as nanoinclusions in the matrix of primary Zn4 Sb3 phase. Elemental mapping by STEM-EDX spectroscopy reveals enrichment of Zn in the secondary Zn6 Sb5 nanoinclusions during the thermal processing without decomposition. Such nanostructures strongly enhances phonon scattering, resulting in a decrease in the thermal conductivity leading to a zT value of 1.4 at 718 K.

Microstructure and chemical data of the thermoelectric ZnSb material after joining to metallic electrodes and heat treatment.

The data presented in this article are related to the research article entitled: "Solder free joining as a highly effective method for making contact between thermoelectric materials and metallic electrodes" (Malik et al., 2017) [1]. This article presents microstructure obtained by scanning electron microscopy (SEM) and chemical analysis by energy dispersive X-ray spectroscopy (EDX) point measurements of the thermoelectric ZnSb legs after joining to metallic electrodes using solder (Zn-2Al) and free-soldering methods.

Discovery of high-performance low-cost n-type Mg3Sb2-based thermoelectric materials with multi-valley conduction bands.

Widespread application of thermoelectric devices for waste heat recovery requires low-cost high-performance materials. The currently available n-type thermoelectric materials are limited either by their low efficiencies or by being based on expensive, scarce or toxic elements. Here we report a low-cost n-type material, Te-doped Mg3Sb1.5Bi0.5, that exhibits a very high figure of merit zT ranging from 0.56 to 1.65 at 300-725 K. Using combined theoretical prediction and experimental validation, we show that the high thermoelectric performance originates from the significantly enhanced power factor because of the multi-valley band behaviour dominated by a unique near-edge conduction band with a sixfold valley degeneracy. This makes Te-doped Mg3Sb1.5Bi0.5 a promising candidate for the low- and intermediate-temperature thermoelectric applications.

The use of dermal graft in severe chordee hypospadias repair: experience from Vietnam.

PURPOSE: Severe chordee with hypospadias may require repair by ventral corporoplasty with a free graft before urethroplasty. We report an 11 year experience with one-stage and two-stage hypospadias repair using dermal grafts. MATERIALS AND METHODS: From 12/1997 to 12/2008, 47 hypospadias with severe chordee were repaired using a ventral dermal graft to correct the chordee. Forty cases were repaired in two stages; the remaining seven patients had adequate preputial skin and were repaired in one stage. In 28 cases the neourethra was covered with both tunica vaginalis and penile dartos flap while 12 were covered only with penile dartos flap. Patients ranged from 12 to 152 months of age. Follow-up ranged from 6 months to 4 years. RESULTS: 28 patients with both tunica vaginalis and dartos flap had 7 urethral fistulas and 2 developed meatal stenosis. 12 patients with only penile dartos flap had 3 fistulas and 2 had meatal regression. The seven patients who underwent a one-stage repair had good results with a straight penis and no evidence of urethral fistula or urethral stenosis. CONCLUSIONS: Dermal graft can be performed in one or two stage hypospadias repair. Complication rates are similar to other standard repairs for proximal hypospadias.

Temperature dependence dynamical permeability characterization of magnetic thin film using near-field microwave microscopy.

A temperature dependence characterization system of microwave permeability of magnetic thin film up to 5 GHz in the temperature range from room temperature up to 423 K is designed and fabricated as a prototype measurement fixture. It is based on the near field microwave microscopy technique (NFMM). The scaling coefficient of the fixture can be determined by (i) calibrating the NFMM with a standard sample whose permeability is known; (ii) by calibrating the NFMM with an established dynamic permeability measurement technique such as shorted microstrip transmission line perturbation method; (iii) adjusting the real part of the complex permeability at low frequency to fit the value of initial permeability. The algorithms for calculating the complex permeability of magnetic thin films are analyzed. A 100 nm thick FeTaN thin film deposited on Si substrate by sputtering method is characterized using the fixture. The room temperature permeability results of the FeTaN film agree well with results obtained from the established short-circuited microstrip perturbation method. Temperature dependence permeability results fit well with the Landau-Lifshitz-Gilbert equation. The temperature dependence of the static magnetic anisotropy H(K)(sta), the dynamic magnetic anisotropy H(K)(dyn), the rotational anisotropy H(rot), together with the effective damping coefficient α(eff), ferromagnetic resonance f(FMR), and frequency linewidth Δf of the thin film are investigated. These temperature dependent magnetic properties of the magnetic thin film are important to the high frequency applications of magnetic devices at high temperatures.

Perineal canal: a special entity of anorectal malformations in Vietnam.

PURPOSE: We report our clinical experience with the perineal canal and suggest the management. MATERIALS AND METHODS: Retrospective chart review of patients with perineal canal were classified by lesion characteristics into Group I: active perineal inflammation, Group II: vulvar excoriation and Group III: no active inflammation. Group III patients underwent primary surgical repair. Group I and II patients underwent repair after medical management. The fistula was repaired by the modified Tsuchida's technique consisting of an anterior anopullthrough and excision of the fistula tract (reverse order). RESULTS: Between September 1999 and August 2003, we treated 120 cases of perineal canal. Group I, II and III consisted of 74, 12 and 34 patients, respectively. In two patients of Group I (2.7%), the fistula tract spontaneously closed. The remaining 118 patients were surgically treated with the modified Tsuchida's technique. Recurrences were similar between patients treated with colostomy (1/28 or 3.6%) versus without colostomy (3/90 or 3.0%), as well as between patients initially treated with primary repair (3/102 or 2.9%) versus patients undergoing reoperation with redo repair (1/16 or 6.25%). CONCLUSIONS: With proper initial medical treatment, the perineal canal could be repaired successfully in one stage with the modified Tsuchida's technique.

Single ectopic ureter: diagnostic value of contrast vaginography.

OBJECTIVES: To present the diagnostic results of contrast vaginography to detect a vaginal ectopic ureter, in addition to investigation with ultrasonography, intravenous urography, and technetium-99m-dimercaptosuccinic acid renal scan. A single ectopic ureter is a rare anomaly. METHODS: Eighteen girls with a single ectopic ureter were treated at the Children's Hospital No. 1 from 1995 to August 2008. The diagnostic studies included ultrasonography, intravenous urography, renal scans, and, finally, vaginography with contrast if the renal scans could not detect the poorly functioning kidneys. RESULTS: Intravenous urography showed a poorly functioning kidney in 1 patient. Another 10 poorly functioning kidneys were revealed by technetium-99m-dimercaptosuccinic acid renal scan, but 7 kidneys were not identifiable using contrast, ultrasonography, or radionuclide. Of these 7 patients, 6 vaginal ectopic ureters were detected using contrast vaginography. All 18 dysplastic kidneys were surgically removed. CONCLUSIONS: The results of the study have demonstrated the satisfactory diagnostic value of vaginography as an imaging technique to detect the dysplastic kidney draining by a single ectopic ureter.