Engineered Bifunctional Luminescent Pillared-Layer Frameworks for Adsorption of CO2 and Sensitive Detection of Nitrobenzene in Aqueous Media.

Through a dual-ligand synthetic approach, five isoreticular primitive cubic (pcu)-type pillared-layer metal-organic frameworks (MOFs), [Zn2 (dicarboxylate)2 (NI-bpy-44)]⋅x DMF⋅y H2 O, in which dicarboxylate=1,4-bdc (1), Br-1,4-bdc (2), NH2 -1,4-bdc (3), 2,6-ndc (4), and bpdc (5), have been engineered. MOFs 1-5 feature twofold degrees of interpenetration and have open pores of 27.0, 33.6, 36.8, 52.5, and 62.1 %, respectively. Nitrogen adsorption isotherms of activated MOFs 1'-5' at 77 K all displayed type I adsorption behavior, suggesting their microporous nature. Although 1' and 3'-5' exhibited type I adsorption isotherms of CO2 at 195 K, MOF 2' showed a two-step gate-opening sorption isotherm of CO2 . Furthermore, MOF 3' also had a significant influence of amine functions on CO2 uptake at high temperature due to the CO2 -framework interactions. MOFs 1-5 revealed solvent-dependent fluorescence properties; their strong blue-light emissions in aqueous suspensions were efficiently quenched by trace amounts of nitrobenzene (NB), with limits of detection of 4.54, 5.73, 1.88, 2.30, and 2.26 µm, respectively, and Stern-Volmer quenching constants (Ksv ) of 2.93×103 , 1.79×103 , 3.78×103 , 4.04×103 , and 3.21×103 m-1 , respectively. Of particular note, the NB-included framework, NB@3, provided direct evidence of the binding sites, which showed strong host-guest π-π and hydrogen-bonding interactions beneficial for donor-acceptor electron transfer and resulting in fluorescence quenching.

MutS protein-based fiber optic particle plasmon resonance biosensor for detecting single nucleotide polymorphisms.

A new biosensing method is presented to detect gene mutation by integrating the MutS protein from bacteria with a fiber optic particle plasmon resonance (FOPPR) sensing system. In this method, the MutS protein is conjugated with gold nanoparticles (AuNPs) deposited on an optical fiber core surface. The target double-stranded DNA containing an A and C mismatched base pair in a sample can be captured by the MutS protein, causing increased absorption of green light launching into the fiber and hence a decrease in transmitted light intensity through the fiber. As the signal change is enhanced through consecutive total internal reflections along the fiber, the limit of detection for an AC mismatch heteroduplex DNA can be as low as 0.49 nM. Because a microfluidic chip is used to contain the optical fiber, the narrow channel width allows an analysis time as short as 15 min. Furthermore, the label-free and real-time nature of the FOPPR sensing system enables determination of binding affinity and kinetics between MutS and single-base mismatched DNA. The method has been validated using a heterozygous PCR sample from a patient to determine the allelic fraction. The obtained allelic fraction of 0.474 reasonably agrees with the expected allelic fraction of 0.5. Therefore, the MutS-functionalized FOPPR sensor may potentially provide a convenient quantitative tool to detect single nucleotide polymorphisms in biological samples with a short analysis time at the point-of-care sites.

Transparent electrode design for AlGaN deep-ultraviolet light-emitting diodes.

Zinc gallate (ZnGa2O4; ZGO) thin films were employed as the p-type transparent contact layer in deep-ultraviolet AlGaN-based light-emitting diodes (LEDs) to increase light output power. The transmittance of 200-nm-thick ZGO in deep-ultraviolet wavelength (280 nm) was as high as 92.3%. Two different ohmic contact structures, a dot-LED (D-LED; ZGO/dot-ITO/LED) and whole-LED (W-LED; ZGO/ITO/LED), exhibited improved light output power and current spreading compared to a conventional ITO-LED (C-LED). At an injection current of 20 mA, the D-LED and W-LED exhibited 33.7% and 12.3% enhancements in light output power, respectively, compared to the C-LED. The enhanced light output power of the D-LED can be attributed to an improvement in current spreading and enhanced light-extracting efficiency achieved by introducing ZGO/dot-ITO.

Performance improvement of vertical ultraviolet-LEDs with AlSi alloy substrates.

A composite AlSi alloy substrate was fabricated to eliminate thermal expansion coefficient mismatch in high-power vertical light-emitting diodes (VLEDs). At 2000-mA injection current, the light output power performance of LED/sapphire, VLED/Si, and VLED/AlSi are 1458, 2465, and 2499 mW and the wall-plug efficiencies are 13.66%, 26.39%, and 28.02%, respectively. The enhanced performance is attributable to the lower tensile stress and series resistance in VLED/AlSi than in LED/sapphire. The surface temperature of LED/AlSi is almost identical to and lower than that of LED/Si and LED/sapphire, respectively. Raman spectroscopy confirms that the residual strain in GaN film bonding on the composite AlSi is lower than that on bulk sapphire.

A new formula based on height for determining endotracheal intubation depth in pediatrics: A prospective study.

STUDY OBJECTIVE: The main objective was to devise an endotracheal intubation formula based on pediatric patients' strongly correlated growth parameters. The secondary objective was to compare the accuracy of the new formula to the age-based formula from Advanced Pediatric Life Support Course (APLS formula) and the middle finger length-based formula (MFL-based formula). DESIGN: A prospective, observational study. SETTING: Operation. PATIENTS: 111 subjects age 4-12 years old undergoing elective surgeries with general orotracheal anesthesia. INTERVENTIONS AND MEASUREMENTS: Growth parameters, including age, gender, height, weight, BMI, middle finger length, nasal-tragus length, and sternum length, were measured before surgeries. Tracheal length and the optimal endotracheal intubation depth (D) were measured and calculated by Disposcope. Regression analysis were used to establish a new formula for predicting the intubation depth. A self-controlled paired design was used to compare the accuracy of the intubation depth between the new formula, APLS formula, and MFL-based formula. MAIN RESULTS: Height (R = 0.897, P < 0.001) was strongly correlated to tracheal length and the endotracheal intubation depth in pediatric patients. New formulae basing on height were established, including new formula 1: D (cm) = 4 + 0.1 × Height (cm) and new formula 2: D (cm) = 3 + 0.1 × Height (cm). Via Bland-Altman analysis, the mean differences for new formula 1, new formula 2, APLS formula and MFL-based formula were - 0.354 cm (95% LOA, -1.289 to 1.998 cm), 1.354 cm (95% LOA, -0.289 to 2.998 cm), 1.154 cm (95% LOA, -1.002 to 3.311 cm), -0.619 cm (95% LOA, -2.960 to 1.723 cm), respectively. The rate of optimal intubation for new formula 1 (84.69%) was higher than for new formula 2 (55.86%), APLS formula (61.26%), and MFL-based formula. (69.37%). CONCLUSIONS: The prediction accuracy for intubation depth of the new formula 1 was higher than the other formulae. The new formula based on height: D (cm) = 4 + 0.1 × Height (cm) was preferable to APLS formula and MFL-based formula with a high incidence of appropriate endotracheal tube position.

[Study on correlation between serum vitamin D level and the curative effect after repair of rotator cuff tears].

OBJECTIVE: To investigate the correlation between serum vitamin D level and clinical outcomes after repair of rotator cuff tears. METHODS: A total 122 patients who met the inclusion criteria and were followed up for 12 months from March 2018 to March 2020 were analyzed retrospectively, including 50 males and 72 females with an average age of(62.10±8.39) years old (ranged, 34 to 82 years old). All patients were divided into deficiency group(vitamin D<20 µg/L) and control group(vitamin D≥20 µg/L), including 62 cases in the deficiency group, with vitamin D (14.80±3.18) µg/L;60 cases in the control group, with vitamin D(25.17±5.64) µg/L. The two groups were compared in terms of age, gender, body mass index(BMI), tear size, degree of retraction, degree of fatty infiltration, injury factors, postoperative pain VAS score, postoperative shoulder joint function score, and re-tear rate. The age of all patients was divided into two categories:<60 years old and ≥60 years old;BMI was divided into <24 kg/m2 and ≥ 24 kg/m2;tear size was divided into ≤3 cm and >3 cm;retraction degree was divided into ≤2 cm and >2 cm;fat infiltration was divided into ≤2 grade and >2 grade;and the course of the disease was ≤3 months and >3 months. The correlation between Sugaya re-tear type and the variables listed above were analyzed and calculated. RESULTS: There were no major complications such as joint infection, anchor withdrawal and revision surgery in any of the 122 patients who were followed up on. There were no statistical differences in age, gender, injury factor, BMI, tear size, degree of retraction, degree of fatty infiltration, and duration of disease between the two groups (P>0.05). The Constant-Murley scores, UCLA scores, and ASES scores of the two groups all improved considerably after surgery(P<0.05);however, there was no statistical differences in the postoperative shoulder function scores between the two groups (P>0.05). There was significant difference in VAS between the two groups 1 month and 3 months after operation, with vitamin D deficiency group scoring higher, and there was no significant differences 6 and 12 months after operation. Tear size(>3 cm), degree of retraction(>2 cm), degree of fatty infiltration(>2 degree) were all shown to be the independent risk factors for retear after surgery by Logistic regression analysis(P<0.05). The comparison between the two groups of patients using a 2×5 row list showed that the Sugaya classification of rotator cuff re-tear(grade Ⅰto Ⅴ) between the vitamin D deficiency group and the control group was statistically different(t=14.228, P=0.007). It was discovered that the Sugaya classification after surgery was statistically different between the two groups. CONCLUSION: Vitamin D deficiency is not correlated with clinical function scores and re-tear rate, however it is associated with the early postoperative pain (1 and 3 months) and the quality of rotator cuff healing (Sugaya classification) after surgery.

Using QRS loop descriptors to characterize the risk of sudden cardiac death in patients with structurally normal hearts.

The predictive value of non-invasive electrocardiographic examination findings for the risk of sudden cardiac death (SCD) in populations with structurally normal hearts remains unclear. This study aimed to investigate the characteristics of the QRS vectorcardiography of surface electrocardiography in patients with structurally normal hearts who experienced SCD. We consecutively enrolled patients who underwent vectorcardiography between March 2017 and December 2018 in a tertiary referral medical center. These patients didn't have structural heart diseases, histories of congestive heart failure, or reduced ejection fraction, and they were classified into SCD (with aborted SCD history and cerebral performance category score of 1) and control groups (with an intervention for atrioventricular node reentrant tachycardia and without SCD history). A total of 162 patients (mean age, 54.3±18.1 years; men, 75.9%), including 59 in the SCD group and 103 in the control group, underwent propensity analysis. The baseline demographic variables, underlying diseases, QRS loop descriptors (the percentage of the loop area, loop dispersion, and inter-lead QRS dispersion), and other electrocardiographic parameters were compared between the two groups. In the univariate and multivariate analyses, a smaller percentage of the loop area (odds ratio, 0.0003; 95% confidence interval, 0.00-0.02; p<0.001), more significant V4-5 dispersion (odds ratio, 1.04; 95% confidence interval, 1.02-1.07; p = 0.002), and longer QRS duration (odds ratio, 1.05; 95% confidence interval, 1.00-1.10; p = 0.04) were associated with SCD. In conclusion, the QRS loop descriptors of surface electrocardiography could be used as non-invasive markers to identify patients experiencing aborted SCD from a healthy population. A decreased percentage of loop area and elevated V4-5 QRS dispersion values assessed using vectorcardiography were associated with an increased risk of SCD in patients with structurally normal hearts.

Gradual replacement of all previously circulating respiratory syncytial virus A strain with the novel ON1 genotype in Lanzhou from 2010 to 2017.

ON1 is a novel genotype of human respiratory syncytial virus (HRSV) subtype A, in children with acute respiratory tract infections (ARTIs). However, there is not much data on the prevalence and clinical and molecular characterization in China.Our study is based on the children who had respiratory infections positive for RSV-A admitted by Gansu Provincial Maternity and Child-care Hospital in Lanzhou (northwestern China) during the last 7 epidemic seasons from 2010 to 2017.In our study, different strains of the novel RSV-A genotype ON1, first identified in Canada in December 2010, were first detected in Gansu Provincial Maternity and Child-care Hospital in August 2012 and then followed by an abrupt expansion in the number of ON1 variants in the beginning of 2014 and eventually replaced all other RSV-A strains from 2015 to 2017. ON1 is characterized by a 72-nt duplication in the C-terminal region of the highly variable attachment glycoprotein (G), predicted to lengthen the polypeptide with 24 amino acids, including a 23-aa duplication, which likely changes antigenicity. New N-glycosylation sites occurred within the 23-aa duplication and 24-aa insertion of the ON1 viruses in our study. Notably, RSV infections occurred later, but peaked sooner from the 2014/2015 to 2016/2017 epidemic seasons, compared with the previous 4 seasons.Our study concluded that genotype ON1 has caused larger outbreaks and became the predominate genotype for HRSV subgroup A in Lanzhou from 2013 to 2017, and became the sole genotype of RSV-A in 2015/2016 and 2016/2017. Our data indicate that northwest of China and the world will eventually be dominated by the ON1 RSV-A genotype, including the possibility for vaccine development. Based on trends seen in RSV-B BA genotype, which predominated for decades, there is a possibility to develop a vaccine for children in the next 10 years.

Structural and Fluorine Plasma Etching Behavior of Sputter-Deposition Yttrium Fluoride Film.

Yttrium fluoride (YF3) films were grown on sapphire substrate by a radio frequency magnetron using a commercial ceramic target in a vacuum chamber. The structure, composition, and plasma etching behavior of the films were systematically investigated. The YF3 film was deposited at a working pressure of 5 mTorr and an RF power of 150 W. The substrate-heating temperature was increased from 400 to 700 °C in increments of 100 °C. High-resolution transmission electron microscopy (HRTEM) and X-ray diffraction results confirmed an orthorhombic YF3 structure was obtained at a substrate temperature of 700 °C for 2 h. X-ray photoelectron spectroscopy revealed a strongly fluorinated bond (Y⁻F bond) on the etched surface of the YF3 films. HRTEM analysis also revealed that the YF3 films became yttrium-oxyfluorinated after exposure to fluorocarbon plasma. The etching depth was three times lower on YF3 film than on Al2O3 plate. These results showed that the YF3 films have excellent erosion resistance properties compared to Al2O3 plates.

Structural and Stress Properties of AlGaN Epilayers Grown on AlN-Nanopatterned Sapphire Templates by Hydride Vapor Phase Epitaxy.

In this paper, we report the epitaxial growth and material characteristics of AlGaN (Al mole fraction of 10%) on an AlN/nanopatterned sapphire substrate (NPSS) template by hydride vapor phase epitaxy (HVPE). The crystalline quality, surface morphology, microstructure, and stress state of the AlGaN/AlN/NPSS epilayers were investigated using X-ray diffraction (XRD), atomic force microscopy (AFM), and transmission electron microscopy (TEM). The results indicate that the crystal quality of the AlGaN film could be improved when grown on the AlN/NPSS template. The screw threading dislocation (TD) density was reduced to 1.4 × 108 cm-2 for the AlGaN epilayer grown on the AlN/NPSS template, which was lower than that of the sample grown on a flat c-plane sapphire substrate (6.3 × 108 cm-2). As examined by XRD measurements, the biaxial tensile stress of the AlGaN film was significantly reduced from 1,187 MPa (on AlN/NPSS) to 38.41 MPa (on flat c-plane sapphire). In particular, an increase of the Al content in the overgrown AlGaN layer was confirmed by the TEM observation. This could be due to the relaxation of the in-plane stress through the AlGaN and AlN/NPSS template interface.

Reduction of Defects in AlGaN Grown on Nanoscale-Patterned Sapphire Substrates by Hydride Vapor Phase Epitaxy.

In this study, a 3-µm-thick AlGaN film with an Al mole fraction of 10% was grown on a nanoscale-patterned sapphire substrate (NPSS) using hydride vapor phase epitaxy (HVPE). The growth mechanism, crystallization, and surface morphology of the epilayers were examined using X-ray diffraction, transmission electron microscopy (TEM), and scanning electron microscopy at various times in the growth process. The screw threading dislocation (TD) density of AlGaN-on-NPSS can improve to 1-2 × 108 cm-2, which is significantly lower than that of the sample grown on a conventional planar sapphire substrate (7 × 108 cm-2). TEM analysis indicated that these TDs do not subsequently propagate to the surface of the overgrown AlGaN layer, but bend or change directions in the region above the voids within the side faces of the patterned substrates, possibly because of the internal stress-relaxed morphologies of the AlGaN film. Hence, the laterally overgrown AlGaN films were obtained by HVPE, which can serve as a template for the growth of ultraviolet III-nitride optoelectronic devices.

Comparison of Erosion Behavior and Particle Contamination in Mass-Production CF4/O2 Plasma Chambers Using Y2O3 and YF3 Protective Coatings.

Yttrium fluoride (YF3) and yttrium oxide (Y2O3) protective coatings prepared using an atmospheric plasma spraying technique were used to investigate the relationship between surface erosion behaviors and their nanoparticle generation under high-density plasma (1012-1013 cm-3) etching. As examined by transmission electron microscopy, the Y2O3 and YF3 coatings become oxyfluorinated after exposure to the plasma, wherein the yttrium oxyfluoride film formation was observed on the surface with a thickness of 5.2 and 6.8 nm, respectively. The difference in the oxyfluorination of Y2O3 and YF3 coatings could be attributed to Y-F and Y-O bonding energies. X-ray photoelectron spectroscopy analyses revealed that a strongly fluorinated bonding (Y-F bond) was obtained on the etched surface of the YF3 coating. Scanning electron microscopy and energy dispersive X-ray diffraction analysis revealed that the nanoparticles on the 12-inch wafer are composed of etchant gases and Y2O3. These results indicate that the YF3 coating is a more erosion-resistant material, resulting in fewer contamination particles compared with the Y2O3 coating.

Recording Characteristics, Microstructure, and Crystallization Kinetics of Ge/GeCu Recording Film Used for Write-Once Blu-Ray Disc.

A Ge67Cu33 (16 nm) layer and a Ge (3 nm)/Ge67Cu33 (16 nm) bilayer were grown by sputtering at room temperature and used as the recording films for write-once blue laser media. In comparison to the crystallization temperature of Ge in a GeCu film (380.7 °C-405.1 °C), the crystallization temperature of Ge in a Ge/GeCu bilayer could be further decreased to 333.7 °C-382.8 °C. The activation energies of Ge crystallization were 3.51 eV ± 0.05 eV and 1.50 eV ± 0.04 eV for the GeCu and the Ge/GeCu films, respectively, indicating that the Ge/GeCu bilayer possesses a higher feasibility in high-speed optical recording applications. Moreover, the lower activation energy would lead to a larger grain size of Ge crystallization in the Ge/GeCu bilayer after the annealing process. Between the as-deposited and the annealed states, the optical contrasts (@ 405 nm) of the GeCu and the Ge/GeCu films were 26.0% and 47.5%, respectively. This reveals that the Ge/GeCu bilayer is more suitable for the recording film of a write-once blu-ray disc (BD-R) in comparison with the GeCu film. Based on the dynamic tests performed for 2× and 4× recording speeds, the optimum jitter values of the BD-R with the Ge/GeCu recording film were 7.4% at 6.3 mW and 7.6% at 8.6 mW, respectively.

Biomechanical analysis of unilateral fixation with interbody cages.

STUDY DESIGN: An in vitro biomechanical study of the stabilizing effects of a different combination of cages and transpedicular instrumentation on experimental degenerative disc disease. OBJECTIVES: To evaluate the biomechanical efficacy of the interbody fusion cage and unilateral posterior instrumentation on the stability of the spine-device construct. SUMMARY OF BACKGROUND DATA: Posterior lumbar interbody fusion (PLIF) has become a clinically established and increasingly popular procedure since its introduction and subsequent modification. Recently, unilateral fixation was reported to have comparable efficacy to bilateral fixation in two- to three-segment posterior instrumentation. This study has been designed to compare biomechanical properties among various spinal fixations, including bilateral versus unilateral fixation with PLIF and cages. METHODS: Thirty porcine L3-L6 spines were separated into six groups. The utilization of one or two cages and unilateral or bilateral instrumentations were reciprocally combined to stabilize the spine with the L4-L5 discectomy, simulating degenerative disc disease. A serial of biomechanical tests, including flexion (5 N-m), extension (5 N-m), compression (250 N), lateral bending (5 N-m), and axial rotation (5 N-m, 25 mm/min), were conducted at the displacement rate of 25 mm/min in five cycles. Stiffness values were derived from loading curves for comparison of spinal stability. RESULTS.: In axial compression, the stiffness of bilateral fixation (BF) and unilateral fixation with two-cage (UF2C) groups were almost identical and only less than that of the bilateral fixation with two cages (BF2C) group. In the flexion, the BF, UF2C, and unilateral fixation with one cage (UF1C) group incurred comparable stiffness to that of the Intact group. In extension, the UF2C group had a comparable stiffness to the BF2C group. In lateral bending, the BF2C group and the UF2C group were the constructs incurring most stiffness. In torsion, the BF group and the UF2C group were less stiff than the BF2C group, but that was statistically insignificant CONCLUSIONS: In the group of unilateral fixation combining PLIF with two cages, the anterior support of cages enabled unilateral instrumentation to restore torsional stiffness and other spinal stability indexes. Considering the initial stability and the load-sharing effect, this study showed that the unilateral fixation combining PLIF and two cages might be a good alternative to spinal fixation.

Biomechanical effects of the body augmenter for reconstruction of the vertebral body.

STUDY DESIGN: An in vitro biomechanical study of the stabilizing effects of the body augmenter and posterior instrumentation on experimental thoracolumbar fractures with vertebral defects. OBJECTIVE: To evaluate the effects of the body augmenter and instrumentation on the stability of the spine-device construct. SUMMARY OF BACKGROUND DATA: Posterior instrumentations alone are widely used to accomplish spinal reduction and provide stability for an injured spine; however, implant failure rates have been reported to be approximately 20%. Transpedicular discectomy and bone graft has reported only 33% fusion rates. Combined anterior bony strut and posterior instrumentation was a challenge to geriatric patients with vulnerable medical conditions and possible vascular and pulmonary complications. Therefore, a new design, the body augmenter, tries to reconstruct the vertebral body through internal mechanical support and also encourage bony fusion. This study is to evaluate its initial mechanical effects. METHODS: Twenty fresh porcine T11-L3 vertebrae were harvested. The L1 vertebra with one third or one half corpectomy was performed to simulate a fracture injury with vertebral defects. Posterior instrumentation alone (PI group), posterior instrumentation with body augmenters (BA group), and anterior instrumentation with tricortical bony strut and DCP 1 level above and 1 level below the fracture site (DCP group) were applied as treatment strategies. Load-displacement and torque-angle plots were generated and used to calculate axial stiffness and torsional rigidity for these constructs with vertebral fracture at the L1 vertebrae. Axial compression, extension, and flexion tests were performed at intact and spine-device constructs to document spinal stability. RESULTS: The construct stability had a complex association to the device applied. In the one third corpectomy group, the BA group had significantly higher compression stiffness than the PI group. In the one half corpectomy group, the flexion and compression stiffness of the BA group became significantly greater than the PI group, and the extension stiffness is significantly higher than the DCP group. CONCLUSIONS: The body augmenters combined with posterior instrumentation increased the spinal construct stability during compression, flexion, and extension. According to results in this study, the body augmenter could provide a better initial stability of construct and prevent the implant failure of posterior instrumentation and may be a feasible substitute for the anterior role in the future.