Designing a magnesium alloy with high strength and high formability.

Although magnesium alloys, as the lightest structural alloys, offer significant potential for automotive applications, their applications remain limited due to their poor formability at room temperature. Since the strategies used for improving formability usually result in a degradation of strength, there are no high strength magnesium alloys showing good formability. Here we report an alloy design concept that can simultaneously provide high strength and good formability. Such designed alloy when subjected to an appropriate processing technique shows a combination of strength and formability that surpasses those of the existing magnesium alloys reported so far. The alloy design concept used in the present study is based on the utilization of alloying elements that can induce precipitation, as well as maximize the segregation of other texture-controlling alloying elements. Such developed alloy is expected to broaden the application of Mg alloy sheets, which are now starting to gain acceptance by automotive industries.

Recombinant growth hormone therapy for prepubertal children with idiopathic short stature in Korea: a phase III randomized trial.

PURPOSE: Several studies have evaluated the effects of growth hormone (GH) on auxological and biochemical parameters in children with non-GH-deficient, idiopathic short stature (ISS). This study evaluated the efficacy and safety of Growtropin®-II (recombinant human GH) in Korean patients with ISS. METHODS: This was a 1-year, open-label, multicenter, phase III randomized trial of Growtropin®-II in Korean patients with ISS. In total, 70 prepubertal subjects (39 males, 31 females) between 4 and 12 years of age were included in the study. All patients were naive to GH treatment. RESULTS: Annual height velocity was significantly higher in the treatment group (10.68 ± 1.95 cm/year) than the control group (5.72 ± 1.72, p < 0.001). Increases in height and weight standard deviation scores (SDSs) at 26 weeks were 0.63 ± 0.16 and 0.64 ± 0.46, respectively, for the treatment group, and 0.06 ± 0.15 and 0.06 ± 0.28, respectively, for the control group (p < 0.001). Serum insulin-like growth factor (IGF-1) and insulin-like growth factor binding protein-3 (IGFBP-3) increased significantly in the treatment group at week 26 compared to baseline. However, the SDS for body mass index (BMI) at 26 weeks did not change significantly in either group. Growtropin®-II was well tolerated and safe over 1 year of treatment. CONCLUSIONS: One-year GH treatment for prepubertal children with ISS demonstrated increased annualized velocity, height and weight SDSs, and IGF-1 and IGFBP-3 levels, with a favorable safety profile. Further evaluations are needed to determine the optimal dose, final adult height, and long-term effects of ISS treatment.

Effect of an obesity prevention program focused on motivating environments in childhood: a school-based prospective study.

BACKGROUND/OBJECTIVES: There has been an increasing global recognition of the need for effective strategies to prevent and control childhood obesity. In this study, we aimed to identify the effectiveness of an obesity prevention program focused on motivating environments in school. SUBJECTS/METHODS: In this school-based, prospective, quasi-experimental study, we enrolled three elementary (fourth graders) and two middle (seventh graders) schools located in Chungju, Korea. We assigned three of the schools to the intervention group and two schools to the control group. The intervention group received 1 year of environmental intervention. Diet- and exercise-related educational video content was provided by internet protocol television services during rest time, and various design materials were painted along the school staircase and hallway to encourage physical activities. Overweight and obese students were recommended to join the summer vacation obesity care program. RESULTS: The final number of total participants was 768 (control 350 and intervention 418). After 1 year of follow-up, there was no significant difference in the overweight/obesity incidence rates and remission rates between the two groups. However, the intervention group showed a greater decrease in the body mass index (BMI) z-score (-0.11 (95% confidence interval (CI) -0.16 to -0.06), P<0.001), increase in height (1.1 cm (95% CI 0.8 to 1.4), P<0.001), reduction of body fat, and increase in muscle mass compared with the control group. In addition, blood pressure (BP) was significantly reduced, and significant improvement in physical fitness followed. In subgroup analysis, students of normal weight, boys and younger participants showed the most beneficial results in weight-related outcomes. In addition, the BP reduction was more pronounced in the higher BMI group, boys and older children. CONCLUSIONS: A simple environmental intervention could effectively influence children. By adding to previously studied strategies, we can develop a more effective obesity prevention program for children.

Triglycerides/glucose index is a useful surrogate marker of insulin resistance among adolescents.

OBJECTIVES: Our aim was to investigate the association between the triglycerides/glucose index (TyG index) and the homeostasis model assessment-estimated insulin resistance (HOMA-IR) in the prediction of insulin resistance (IR) among adolescents. METHODS: We conducted a cross-sectional study among 221 Korean adolescents (168 males and 53 females aged 9-13 years) from May to June 2014 in Chung-ju city. The TyG index was calculated as ln [triglycerides (mg dl-1) × fasting glucose (mg dl-1)/2]. IR was defined using HOMA-IR >95th percentile for age and sex. RESULTS: In the IR group, weight, body mass index (BMI), waist circumference, body fat, fasting insulin, fasting plasma glucose, triglyceride levels and triglycerides/high-density lipoprotein cholesterol (TG/HDL-C) were significantly higher than that in the non-IR group. The TG index was significantly different between the IR group (n=22) and non-IR group (n=199), at 8.43±0.45 and 8.05±0.41, respectively (P<0.001). The TyG index was well correlated with HOMA-IR (r=0.41; P<0.001) and showed a strong positive association with TG/HDL-C (r=0.84; P<0.001). The cut-off of the TyG index for diagnosis of insulin resistance was 8.18. CONCLUSIONS: The TyG index is a simple, cost-effective surrogate marker of insulin resistance among adolescents compared with HOMA-IR.

Large linear magnetoresistance in heavily-doped Nb:SrTiO3 epitaxial thin films.

Interaction between electrons has long been a focused topic in condensed-matter physics since it has led to the discoveries of astonishing phenomena, for example, high-Tc superconductivity and colossal magnetoresistance (CMR) in strongly-correlated materials. In the study of strongly-correlated perovskite oxides, Nb-doped SrTiO3 (Nb:SrTiO3) has been a workhorse not only as a conducting substrate, but also as a host possessing high carrier mobility. In this work, we report the observations of large linear magnetoresistance (LMR) and the metal-to-insulator transition (MIT) induced by magnetic field in heavily-doped Nb:STO (SrNb0.2Ti0.8O3) epitaxial thin films. These phenomena are associated with the interplay between the large classical MR due to high carrier mobility and the electronic localization effect due to strong spin-orbit coupling, implying that heavily Nb-doped Sr(Nb0.2Ti0.8)O3 is promising for the application in spintronic devices.

Who may benefit from robotic gastrectomy?: A subgroup analysis of multicenter prospective comparative study data on robotic versus laparoscopic gastrectomy.

AIMS: Robotic gastrectomy for gastric cancer has been proven to be a feasible and safe minimally invasive procedure. However, our previous multicenter prospective study indicated that robotic gastrectomy is not superior to laparoscopic gastrectomy. This study aimed to identify which subgroups of patients would benefit from robotic gastrectomy rather than from conventional laparoscopic gastrectomy. METHODS: A prospective multicenter comparative study comparing laparoscopic and robotic gastrectomy was previously conducted. We divided the patients into subgroups according to obesity, type of gastrectomy performed, and extent of lymph node dissection. Surgical outcomes were compared between the robotic and laparoscopic groups in each subgroup. RESULTS: A total of 434 patients were enrolled into the robotic (n = 223) and laparoscopic (n = 211) surgery groups. According to obesity and gastrectomy type, there was no difference in the estimated blood loss (EBL), number of retrieved lymph nodes, complication rate, open conversion rate, and the length of hospital stay between the robotic and laparoscopic groups. According to the extent of lymph node dissection, the robotic group showed a significantly lower EBL than did the laparoscopic group after D2 dissection (P = 0.021), while there was no difference in EBL in patients that did not undergo D2 dissection (P = 0.365). CONCLUSION: Patients with gastric cancer undergoing D2 lymph node dissection can benefit from less blood loss when a robotic surgery system is used.

Spin dynamics in Na(4-x)Ir3O8 (x = 0.3 and 0.7) investigated by ²³Na NMR and µSR.

We report (23)Na nuclear magnetic resonance (NMR) and zero-field (ZF) and longitudinal-field (LF) muon spin relaxation (µSR) measurements of the depleted hyperkagome compounds Na(4-x)Ir3O8 (x = 0.3 and 0.7), which undergo an insulator-semimetal transition as a function of x. The (23)Na spin-lattice relaxation rates, T1(-1), follow a T(2.5) power law behavior at accessible temperatures of T = 120-350 K. A substantial temperature dependence of T1(-1) indicates the presence of gapped excitations at elevated temperatures through the transition to a semimetallic phase. ZF-µSR results reveal that hole-doping leads to a melting of quasi-static order to a dynamically fluctuating state. The very slow muon depolarization rate which varies hardly with temperature indicates that spins are close to an itinerant limit in the largest doping x = 0.7. The dynamic relaxation rates extracted from the LF-µSR spectra show a three-dimensional diffusive transport. Our combined NMR and µSR results suggest the occurrence of intriguing spin and charge excitations across the insulator-semimetal transition.

Low albumin-to-globulin ratio associated with cancer incidence and mortality in generally healthy adults.

BACKGROUND: Chronic inflammation is known to be one of the main steps in carcinogenesis. Identification of those with chronic inflammation may help identify subjects at risk of cancer. Previous studies have reported low albumin-to-globulin ratio (AGR) to be associated with increased cancer mortality in cancer patients, but there has been no study based on healthy populations. PATIENTS AND METHODS: Our retrospective cohort study involved 26 974 generally healthy adults aged 30 or older who visited Seoul National University Hospital Health Promotion Center for self-referred health checkup. National medical service claims data were used to determine cancer incidence, and Korean death registry data was used to determine mortality. Median follow-up time for survival was 5.9 years (interquartile range 4.1 years). RESULTS: Compared with subjects with AGR ≥ 1.5, subjects with 1.1 > AGR ≥ 1.0 and 1.0 > AGR showed adjusted hazard ratio (aHR) 2.69 (95% confidence interval, CI, 1.54-4.72) and aHR 6.71 (95% CI 3.56-12.66) for all-cause mortality, aHR 2.95 (95% CI 1.42-6.11) and aHR 4.38 (95% CI 1.57-12.25) for cancer mortality, and aHR 2.07 (95% CI 1.28-3.36) and aHR 3.99 (95% CI 2.10-7.58) for cancer incidence, respectively. When cancer incidence events after 2 years from baseline were separately analyzed, subjects with 1.1 > AGR ≥ 1.0 and 1.0 > AGR were associated with aHR 1.88 (95% CI 1.01-3.48) and aHR 2.55 (95% CI 1.03-7.11) for cancer incidence, respectively. Cancer events were increased in all types of cancer, but especially in liver and hematologic malignancies. CONCLUSIONS: Low AGR is a risk factor for cancer incidence and mortality, both short- and long terms, in a generally healthy screened population. The results of this study need to be replicated in larger studies, along with the determination of the sensitivity and other diagnostic values of low AGR.

Impact of BMI on the incidence of metabolic abnormalities in metabolically healthy men.

OBJECTIVES: Although the existence of metabolically healthy obese (MHO) individuals has been recognized, little is known regarding metabolic health status in these subjects over time. Thus, we evaluated longitudinal changes in metabolic parameters among MHO subjects compared with metabolically healthy, normal-weight (MHNW) subjects. METHODS: A cohort study was performed on 2599 Korean men, 30-59 years of age, with no evidence of fatty liver disease on ultrasound and no traits of metabolic syndrome at baseline. BMI was categorized based on criteria for Asian population. Study participants were followed annually or biennially between 2002 and 2009. At each visit, the fatty liver on ultrasound was assessed and metabolic abnormalities were measured. Parametric Cox models and a pooled logistic regression models were used to evaluate the relationships of BMI with incident metabolic abnormalities. RESULTS: During 9647.1 person-years of follow-up, 1673 participants developed metabolic abnormalities. After adjusting for age, smoking, alcohol intake and exercise, higher baseline BMI categories predicted increased incidences of metabolic abnormalities in a dose-response manner. The hazard ratios (95% confidence intervals) for hypertriglyceridemia, prediabetes, pre-hypertension, low high-density lipoprotein-cholesterol, fatty liver, elevated high sensitivity-C reactive protein, elevated homeostasis model assessment of insulin resistance, any metabolic abnormality and metabolic syndrome among the MHO subjects compared with the MHNW subjects were 1.51 (1.23-1.85), 1.43 (1.19-1.72), 1.79 (1.45-2.22), 1.80 (1.30-2.49), 2.69 (2.19-3.31), 1.39 (1.16-1.67), 2.90 (2.31-3.62), 1.68 (1.45-1.93) and 1.84(1.02-3.30), respectively. CONCLUSION: In this study, MHO individuals showed higher incidences of metabolic abnormalities compared with MHNW individuals. This suggests that initially MHO individuals undergo adverse metabolic changes associated with obesity over time.

Effect of tubular orientation on the dentin bond strength of acidic self-etch adhesives.

OBJECTIVE: To determine the effect of varying the adhesive pH on the bond strength of an experimental self-etch adhesive system (BISCO, Inc) to dentin with the bonding surface perpendicular (occlusal direction) or parallel (axial direction) to dentin tubules. METHODS: An experimental self-etch adhesive was modified by adding base to increase the pH from 1.1 to 2.7. Shear bond strength (SBS) was measured using an Ultradent jig method with Aelite All-Purpose Body light-cured composite (BISCO, Inc). Human dentin was prepared by exposing the axial and occlusal surface. The self-etch adhesive was applied according to the manufacturer's instructions and cured for 10 seconds@ 500mW using a VIP (BISCO, Inc) halogen curing light. Scanning electron microscope (SEM) examination was used to view both the occlusal- and axial-oriented dentin surfaces that were etched using pH (1.2~3.0) adjusted phosphoric acid solutions. All bond strength data analysis was performed using ANOVA, followed by a Student-Newman-Keuls multiple range test. RESULTS: When the dentin-bonding surface was parallel to the tubule orientation (axial), the bond strength was independent of the pH of the self-etch adhesive (p>0.05). When the bonded surface was perpendicular to the tubule orientation (occlusal), the bond strength numbers were decreased as the pH decreased; the decrease became statistically significant when the pH was lower than 1.8. With a pH higher than 2.3, the bond strength had no difference (p>0.05) between the occlusal and axial positions. When the pH was lower than 1.8, SEM pictures confirmed that the smear layers and smear plugs were completely solubilized by the phosphoric acid solution. Higher pH values (2.0­2.8) showed smear layers partially solubilized and pH values of 3.0 fully retained the smear layer.

Early-onset Charcot-Marie-Tooth patients with mitofusin 2 mutations and brain involvement.

Mutations of the mitofusin 2 (MFN2) gene have been reported to be the most common cause of the axonal form of Charcot-Marie-Tooth disease (CMT). A prospective brain MRI study was performed on 18 early-onset CMT patients with MFN2 mutations, and a high frequency (39%) of brain abnormalities was found. Early-onset patients showed multiple scattered or confluent brain lesions that involved gray matter as well as white matter. Patterns of brain involvement in early-onset patients differed from those of late-onset patients and other hereditary peripheral neuropathies. In addition, one CMT patient demonstrated a brain lesion before the development of peripheral neuropathy.

Effects of restoration and substrate on polymerization contraction stress of dental composites.

The aim of this study was to treat both restoration and substrate as a combined factor (RS-factor) to complement the popular C-factor in prediction of polymerization contraction stress (PCS). A simple model consists of a uniaxial restoration with a curing composite sandwiched between two solid mountings (substrates). By using the equal stress principle and taking into account substrate deformation, a set of equations were developed and solved, resulting in a mathematical relationship between PCS and the size and stiffness of the substrate and the restoration. The strain gage method was used to experimentally assess the PCS of a light-cured composite encircled in an aluminum ring. Differently sized inserts made of cured composites and glass were placed in the center of the ring to control the thickness of the composite to be cured and created different RS factors as well as C-factors. According to the model, a restoration with a small RS-factor will produce a high PCS. The model also predicts that a restoration with a small C-factor will have a high PCS because of the compliance of substrates. These predictions were tentatively confirmed by the strain gage measurements. A higher PCS was detected when a smaller insert was used, which created a smaller RS-factor or C-factor, or when a glass insert was used instead of a less stiff composite insert, in which the former created a smaller RS-factor. The RS-factor may be a dominant factor in determining the PCS outcome in some special cases.

Management and clinical outcome of acute basilar artery dissection.

BACKGROUND AND PURPOSE: There have been inconsistencies on the prognosis and controversies as to the proper management of acute basilar artery dissection. The aim of this study was to evaluate acute basilar artery dissection and its outcome after management. MATERIALS AND METHODS: A total of 21 patients (mean age, 53 years; range, 24-78 years) with acute basilar artery dissection were identified between January 2001 and October 2007. Clinical presentation, management, and outcomes were retrospectively evaluated. RESULTS: The patients presented with subarachnoid hemorrhage (n = 10), brain stem ischemia (n = 10), or stem compression sign (n = 1). Ruptured basilar artery dissections were treated by stent placement with coiling (n = 4), single stent placement (n = 3), or conservatively (n = 3). Of the patients treated with endovascular technique, 6 had favorable outcome (modified Rankin scale [mRS], 0-2) and the remaining patient, who was treated by single stent placement, died from rebleeding. All 3 conservatively managed patients experienced rebleeding, of whom 2 died and the other was moderately disabled. Unruptured basilar artery dissections were treated conservatively (n = 7) or by stent placement (n = 4). Of the patients with unruptured basilar artery dissection, 9 had favorable outcome and the remaining 2 patients, both of whom were conservatively managed, had poor outcome because of infarct progression. The group with the ruptured basilar artery dissection revealed a higher mortality rate than the group with the unruptured dissection (30% vs 0%). The group treated with endovascular means revealed more favorable outcome than the group that was treated with conservative measures (90.9% vs 50%). CONCLUSION: The ruptured basilar artery dissections were at high risk for rebleeding, resulting in a grave outcome. Stent placement with or without coiling may be considered to prevent rebleeding in ruptured basilar dissections and judiciously considered in unruptured dissections with signs of progressive brain stem ischemia.

Different clinical and magnetic resonance imaging features between Charcot-Marie-Tooth disease type 1A and 2A.

Charcot-Marie-Tooth disease type 1A (CMT1A) is the more frequent cause of demyelinating CMT, and CMT2A is the most common cause of axonal CMT. We conducted a magnetic resonance imaging (MRI) study on 39 CMT1A and 21 CMT2A patients to compare their neuroimaging patterns and correlate with clinical features. CMT1A patients showed selective fatty infiltration with a preference for anterior and lateral compartment muscles, whereas CMT2A patients showed a preference for superficial posterior compartment muscles. Early-onset CMT2A patients showed more severe leg fatty atrophy than late-onset CMT2A patients. In late-onset CMT2A, soleus muscle was the earliest, and most severely affected than the other leg muscles. Selective involvement of intrinsic foot muscles is a characteristic pattern of minimal CMT1A and CMT2A. Our MRI study demonstrates different patterns of fatty infiltration involving superficial posterior compartment muscles in CMT2A (partial T-type), and peroneal nerve innervated muscles in CMT1A (P-type).

Broadband electron spin resonance at low frequency without resonant cavity.

We have developed a nonconventional broadband electron spin resonance (ESR) spectrometer operating continuously in the frequency range from 0.5 to 9 GHz. Dual antenna structure and the microwave absorbing environment differentiate the setup from the conventional one and enable broadband operation with any combination of frequency or magnetic field modulation and frequency or magnetic field sweeping. Its performance has been tested with the measurements on a 1,1-diphenyl-2-picrylhydrazyl (DPPH) sample and with the measurements on the single molecular magnet, V6, in solid state at low temperature.

Concurrent delivery of GM-CSF and B7-1 using an oncolytic adenovirus elicits potent antitumor effect.

Oncolytic adenoviral vectors are currently being developed as biologic anticancer agents. Coupling the lytic function of an oncolytic adenovirus (Ad) with its ability as a transgene delivery system represents a powerful extension of this methodology. A clear advantage is the amplification of a therapeutic gene, as replicating vectors would be able to infect and deliver the gene of interest to neighboring cells. Granulocyte-macrophage colony-stimulating factor (GM-CSF) is one of the most potent stimulators of a specific and long-lasting antitumor immunity and its important role in the maturation of antigen-presenting cells to induce T-cell activation has been well documented. Similarly, the B7 family has also been shown to play an integral role in mediating an antitumor response. Most tumor cells, however, lack the expression of these costimulatory molecules on their surface, thus escaping immune system recognition. To increase the antitumor effect of an oncolytic Ad, we have generated an E1B 55 kDa-deleted oncolytic adenoviral vector, YKL-GB, that expresses both GM-CSF and B7-1. The therapeutic efficacy of YKL-GB Ad was evaluated in immunocompetent mice bearing murine melanoma B16-F10 tumors. Significant inhibition of tumor growth was seen in mice treated with YKL-GB compared to those treated with the analogous vector, YKL-1. Moreover, YKL-GB oncolytic Ad demonstrated enhanced antitumor activity and higher incidences of tumor regression compared to a replication-incompetent Ad, dl-GB, which coexpresses GM-CSF and B7-1. Localized GM-CSF and B7-1 gene transfer also conferred long-lasting immunity against a tumor re-challenge. To establish that the observed antitumor effect is associated with the generation of a tumor-specific immune response, we carried out interferon-gamma enzyme-linked immune spot assay. We observed that YKL-GB induced significantly higher immune cell activation than YKL-1. Furthermore, immunohistochemical studies demonstrated robust dendritic cells and CD4(+)/CD8(+) T-cell infiltration in these mice compared to the YKL-1-treated groups. In agreement with these results, splenocytes from tumor-bearing mice treated with YKL-GB expressed high levels of the costimulatory and activation molecules. These findings demonstrate the effectiveness of enhancing the immune response against tumors with an oncolytic Ad expressing both GM-CSF and B7-1 and provide a potential therapeutic strategy for the management of neoplasia.

A mechanism on why slower polymerization of a dental composite produces lower contraction stress.

It has been well documented that the rate of polymerization of a dental composite often affects its polymerization contraction stress. In most cases, a slower cure produces a lower stress. To investigate the mechanism behind this, we prepared an unfilled dimethacrylate resin sample and photocured it using two light irradiances, both with the same total irradiation energy. We measured the polymerization-induced shrinkage from the unbonded surface of a class I restoration, contraction stress, extent of polymerization, and flexural modulus. The resin specimens cured under the two irradiances achieved the same extent of polymerization and developed an identical amount of shrinkage from the unbonded surface. But those cured under the lower irradiance possessed a lower contraction stress and a lower flexural modulus than those cured under the higher irradiance. We demonstrated that the stress level did not respond to the extent of viscous flow of the curing resin because the slower polymerization did not produce more shrinkage from the unbonded surface. Instead, the lower stress is likely due to a lower modulus of the cured resin. To explain why the cured resin with an identical extent of polymerization can have different moduli, we proposed that slower polymerization produces a higher level of structural inhomogeneity, which reduces the rigidity of the cured resin.