Defect Engineering Strategy for Superior Integration of Metal-Organic Framework and Halide Perovskite as a Fluorescence Sensing Material

Combining halide perovskite quantum dots (QDs) and metal-organic frameworks (MOFs) material is challenging when the QDs' size is larger than the MOFs' nanopores. Here, we adopted a simple defect engineering approach to increase the size of zeolitic imidazolate framework 90 (ZIF-90)'s pores size to better load CH3NH3PbBr3 perovskite QDs. This defect structure effect can be easily achieved by adjusting the metal-to-ligand ratio throughout the ZIF-90 synthesis process. The QDs are then grown in the defective structure, resulting in a hybrid ZIF-90-perovskite (ZP) composite. The QDs in ZP composites occupied the gap of 10-18 nm defective ZIF-90 crystal and interestingly isolated the QDs with high stability in aqueous solution. We also investigated the relationship between defect engineering and fluorescence sensing, finding that the aqueous Cu2+ ion concentration was directly correlated to defective ZIF-90 and ZP composites. We also found that the role of the O-Cu coordination bonds and CH3NHCu+ species formation in the materials when they reacted with Cu2+ was responsible for this relationship. Finally, this strategy was successful in developing Cu2+ ion fluorescence sensing in water with better selectivity and sensitivity.

Multiresponsive Self-Healing Lanthanide Fluorescent Hydrogel for Smart Textiles

Lanthanide organometallic complexes exhibit strong luminescence characteristics, owing to their antenna effects. The f-d energy level transition causes this phenomenon, which occurs when ligands and the external electrons of lanthanide metals coordinate. Based on this phenomenon, we used two lanthanide metals, europium (Eu) and terbium (Tb), in the present study as the metal center for iminodiacetic acid ligands. Further, we developed the resulting fluorescent organometallic complex as a smart material. The ligand-metal bond in the material functioned as a metal chelating agent and a cross-linking agent in a dynamically coordinated form, thereby prompting the material to self-heal. Temperature-sensitive poly-N-isopropylacrylamide was incorporated into the material as the polymer backbone. Afterward, we combined it with water-soluble poly(vinyl alcohol) and an additional ligand from poly(acrylic acid) to fabricate a high-performance hydrogel composite material. The shrinkage and expansion of the polymer form a grid between the materials. Because of the different coordination stabilities of Eu3+ and Tb3+, the corresponding material exhibits environmental responses toward excitation wavelength, temperature, and pH, thus generating different colors. When used in fabrics, the cross-linking mechanism of the material effectively looped the material between fabric fibers; furthermore, the temperature sensitivity of the polymer adjusted the size of pores between fabric fibers. At relatively higher temperatures (>32 °C), the polymer structure shrank, fiber pores expanded, and air permeability improved. Thus, this material appears to be promising for use in smart textiles.

Evaluating online learning engagement of nursing students

BACKGROUND

Previous studies suggest that increased learning satisfaction may encourage learning engagement in an online learning environment.

OBJECTIVES

To evaluate the level of learning engagement and its relationship with students' perceived learning satisfaction in an online clinical nursing elective course.

DESIGN

A prospective interventional study.

SETTINGS

A nursing course was converted to an online format because of the coronavirus disease COVID pandemic.

PARTICIPANTS

Part-time post-registration nursing undergraduates enrolled in an elective online clinical course.

METHODS

Related teaching and learning strategies were deployed in the course using the Community of Inquiry framework. All students who completed the course were invited to complete an online survey that included a validated Online Student Engagement questionnaire (OSE). Pearson's correlations were used to determine the association between perceived learning satisfaction and learning engagement. A logistic regression model was used to explore the associations of gender, age, working experience and perceived learning satisfaction with higher learning engagement.

RESULTS

The questionnaires were completed by 56 of 68 students (82%). The Pearson's correlation coefficient between the mean perceived learning satisfaction and OSE scores was 0.75 (p < .001). Twenty-five students (45%) were identified as highly engaged, using a cut-off of ≥3.5 for the mean OSE score. The mean perceived learning satisfaction (SD) score differed significantly between highly engaged and not highly engaged students [4.02 (0.49) vs. 3.27 (0.62), p < .001]. The logistic regression model showed that a greater perceived learning satisfaction [adjusted odds ratio (OR): 17.2, 95% C.I.: 3.46-86.0, p = .001] was associated with an increased likelihood of higher learning engagement, and >1 year of working experience (adjusted OR: 0.11, 95% C.I.: 0.01-0.89, p = .0039) was associated with a decreased likelihood of higher learning engagement.

CONCLUSIONS

The study findings suggest that perceived learning satisfaction predicts learning engagement among nursing students in this online learning course.

Severe myocardial bridge presenting as paroxysmal atrioventricular block

Chest pain complicated with electrocardiographic changes is not an uncommon scenario in emergency departments, which should be examined cautiously. We describe a 51-years-old man with a myocardial bridge of coronary artery presenting with simultaneous Mobitz type I atrioventricular block on electrocardiography. Echocardiography excluded valvular abnormality and systolic/diastolic dysfunction. Coronary angiography confirmed the diagnosis of a myocardial bridge at the middle segment of the left anterior descending artery, involving the most dominant septal perforator branch with marked systolic compression. The patient underwent coronary artery bypass grafting surgery and was followed up uneventfully at the outpatient department with medical treatment of diltiazem and clopidogrel. The present case is being reported to highlight that clinicians should be alert to such a congenital abnormality as a potential cause of repeated myocardial infarction and conduction abnormality.

Simultaneous Broadening and Enhancement of Cr3+ Photoluminescence in LiIn2 SbO6 by Chemical Unit Cosubstitution: Night-Vision and Near-Infrared Spectroscopy Detection Applications

Near-infrared (NIR)-emitting phosphor materials have been extensively developed for optoelectronic and biomedical applications. Although Cr³⁺ -activated phosphors have been widely reported, it is challenging to achieve ultra-broad and tunable NIR emission. Here, a new ultra-broadband NIR-emitting LiIn₂ SbO₆ :Cr³⁺ phosphor with emission peak at 965 nm and a full-width at half maximum of 217 nm is reported. Controllable emission tuning from 965 to 892 nm is achieved by chemical unit cosubstitution of [Zn²⁺ -Zn²⁺ ] for [Li⁺ -In³⁺ ], which can be ascribed to the upshift of ⁴ T_2g energy level due to the strengthened crystal field. Moreover, the emission is greatly enhanced, and the FWHM reaches 235 nm. The as-prepared luminescent tunable NIR-emitting phosphors have demonstrated the potential in night-vision and NIR spectroscopy techniques. This work proves the feasibility of chemical unit cosubstitution strategy in emission tuning of Cr³⁺ -doped phosphors, which can stimulate further studies on the emission-tunable NIR-emitting phosphor materials.

High-efficiency picosecond mode-locked laser using a thulium-doped nanoengineered yttrium-alumina-silica fiber as the gain medium

We report the theoretical and experimental investigation of a self-starting mode-locked fiber laser with a nanoengineered Tm³⁺-doped yttrium-alumina-silica (YAS) fiber as the gain medium. The YAS fiber exhibits a higher capability of Tm³⁺ cluster elimination than commercial silica fibers. The Tm³⁺ fluorescence properties and YAS dispersion are well characterized. As a result, an efficient picosecond mode-locked fiber laser is demonstrated with a slope efficiency of 14.14% and maximum pulse energy of 1.27 nJ. To the best of our knowledge, this is the first mode-locked fiber laser based on a Tm³⁺-doped YAS fiber. The experimental observation is also supported by the numerical analysis.

P5644Hypoglycemic episodes increase the risk of ventricular arrhythmias and sudden cardiac arrest in patients with type 2 diabetes - a nationwide cohort study

Background

Hypoglycemic episode (HE) increases the risk of cardiovascular mortality. The impact of HE on the risk of sudden death remains unclear. We hypothesized that HE increases the risks of ventricular arrhythmia (VA) and sudden cardiac arrest (SCA), and that anti-diabetic agents (ADAs) causing hypoglycemia also increase the risks of VA and SCA.

Methods

Patients aged ≥20 years with newly diagnosed diabetes were identified from the Taiwan National Insurance Database. HE was defined as the presentation of hypoglycemic coma or specified/unspecified hypoglycemia. For control group, we included diabetic patients without HE, and they were frequency-matched to the HE group at a 4:1 ratio. The primary outcome was the occurrence of any event of VA (including ventricular tachycardia and fibrillation) and SCA during the defined follow-up periods. Multivariate Cox hazards regression model was used to evaluate the hazard ratio (HR) for VA or SCA.

Results

A total of 54,303 diabetic patients were screened with 1,037 of them in the HE group, and 4,148 in the control group. During a mean follow-up period of 3.3±2.5 years, 29 VA/SCA events had occurred. Compared to the control group, the HE group had a higher incidence of VA/SCA (adjusted HR: 2.42, p=0.04). Diabetic patients medicated with insulin for glycemic control increased the risk of VA/SCA compared to those without insulin (adjusted HR: 3.05, p=0.01).

Kaplan-Meier survival curves

Conclusions

HEs in patients with diabetes increased the risks of VA and SCA compared to those without. Their use of insulin also independently increased the risk of VA/SCA.

Pre-treatment quality of life as a predictor of distant metastasis-free survival and overall survival in patients with head and neck cancer who underwent free flap reconstruction

PURPOSE

This study examined the prognostic associations of pre-treatment quality of life (QoL) with overall survival (OS) and distant metastasis-free survival (DFMS) among patients with head and neck cancer (HNC) who underwent free flap reconstruction.

METHODS

A cohort of 127 HNC patients who received free flap reconstruction between November 2010 and June 2014 at a hospital were recruited. Pre-treatment QoL was measured by the University of Washington Quality of Life Questionnaire, which contains six physical domains, including speech, swallowing, appearance, saliva, taste and chewing, as well as the six social-emotional domains of pain, activity, recreation, shoulder, mood, and anxiety. Cox regression analyses were performed.

RESULTS

Results showed that pre-treatment QoL was predictive of OS and DMFS. Of the domains, swallowing, chewing, speech, taste, saliva, pain and shoulder were demonstrated to be significant predictors of OS. Additionally, swallowing, chewing, speech, pain and activity were demonstrated making significant contributions to DMFS.

CONCLUSION

Our data supported that physical domains of pre-treatment QoL were predictors for OS and DFMS in HNC patients with free-flap reconstruction. Longitudinal studies are warranted to clarify the prognostic abilities of social-emotional domains. Information on pre-treatment QoL should be taken into account to individualize care plan for these patients, and hence prolong their survival.

[The role and mechanism of 2-deoxyglucose in reversing osimertinib-acquired resistance of non-small cell lung cancer cell line]

Objective: To explore the role and mechanism of 2-deoxyglucose (2-dg) in reversing osimertinib- acquired resistance of non-small cell lung cancer(NSCLC)cell line. Methods: The NSCLC line H1975 (purchased from the American Type Culture Collection) was conducted by induction method in vitro to construct the osimertinib-resistance NSCLC cell line H1975-OR. The osimertinib-resistance of H1975-OR cell line was examined by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, colony-formation assay, Ki67 incorporation assay and the expression of apoptosis-related protein. The glycolysis level was assayed by the lactic acid production measured in the culture medium supernatant of H1975 and H1975-OR. The expression of glycolysis key enzymes (HK2, GLUT1, P-PKM2) and apoptosis-related protein (BIM, Bcl-2) were detected by Western blot. The cells were divided into control group, 2-deoxyglucose (4 mmol/L) monotherapy group, osimertinib (3 μmol/L) monotherapy group and 2-deoxyglucose (4 mmol/L)+ osimertinib (3 μmol/L) combination therapy group, then the apoptosis rate of cells was measured by flow cytometry to evaluate the pro-apoptotic ability of drugs. Date were analyzed by Independent-Samples t-test using SPSS 16.0 statistical software. Results: The glycolysis level of osimertinib-sensitive cell line H1975 was lower than that of osimertinib-resistance cell line H1975-OR [the yield of lactic acid, respectively, was (21.0±0.9) and (26.5±2.8) mmol·L(-1)·10(4)cells(-1), P<0.05]. The osimertinib- acquired resistance of H1975-OR could be reversed by 4 mmol/L 2-deoxyglucose(the IC(50) value of osimertinib in H1975-OR cell line decreased from (7.0±1.9) μmol/L to (1.4±0.1) μmol/L, which was close to the IC(50) value of osimertinib in H1975 cell line (1.0±0.2) μmol/L. The apoptosis rate of H1975-OR was significantly higher in 2-deoxyglucose + osimertinib combination therapy group (26.7±2.4)%, compared to control group (5.1±0.7)%, 2-deoxyglucose monotherapy group (6.1±2.5)% and osimertinib monotherapy group (11.4±2.7)%(all P<0.05). The expression of pro-apoptotic protein BIM in H1975-OR was significantly higher in 2-deoxyglucose+ osimertinib combination therapy group (177.8±28.1)% and the expression of anti-apoptotic protein Bcl-2 in H1975-OR was significantly lower in 2-deoxyglucose+ osimertinib combination therapy group (24.6±5.2)%, compared to control group (100±0)%, all P<0.05. Conclusion: 2-deoxyglucose can reverse the acquired resistance of NSCLC cell line to osimertinib, which may be related to the inhibition of cell glycolysis and the induction of apoptosis.

Novel Fluorescence Sensor Based on All-Inorganic Perovskite Quantum Dots Coated with Molecularly Imprinted Polymers for Highly Selective and Sensitive Detection of Omethoate

All-inorganic cesium lead halide perovskites (CsPbX₃, X = Cl, Br, and I) have attracted considerable attention with superior electrical and photophysical properties. In this study, luminescent perovskite (CsPbBr₃) quantum dots (QDs) as sensing elements combined with molecularly imprinted polymers (MIPs) are used for the detection of omethoate (OMT). The new MIPs@CsPbBr₃ QDs were synthesized successfully through the imprinting technology with a sol-gel reaction. The fluorescence (FL) of the MIPs@CsPbBr₃ QDs was quenched obviously on loading the MIPs with OMT, the linear range of OMT was from 50 to 400 ng/mL, and the detection limit was 18.8 ng/mL. The imprinting factor was 3.2, which indicated excellent specificity of the MIPs for the inorganic metal halide (IMH) perovskites. The novel composite possesses the outstanding FL capability of CsPbBr₃ QDs and the high selectivity of molecular imprinting technology, which can convert the specific interactions between template and the imprinted cavities to apparent changes in the FL intensity. Hence, a selective and simple FL sensor for direct and fast detection of organophosphorus pesticide in vegetable and soil samples was developed here. The present work also illustrates the potential of IMH perovskites for sensor applications in biological and environmental detection.

Water-Resistant Efficient Stretchable Perovskite-Embedded Fiber Membranes for Light-Emitting Diodes

Cesium lead halide perovskite nanocrystals (NCs) with excellent intrinsic properties have been employed universally in optoelectronic applications but undergo hydrolysis even when exposed to atmospheric moisture. In the present study, composite CsPbX₃ (X = Cl, Br, and I) perovskite NCs were encapsulated with stretchable (poly(styrene-butadiene-styrene); SBS) fibers by electrospinning to prepare water-resistant hybrid membranes as multicolor optical active layers. Brightly luminescent and color-tunable hydrophobic fiber membranes (FMs) with perovskite NCs were maintained for longer than 1 h in water. A unique remote FMs packaging approach was used in high-brightness perovskite light-emitting diodes (PeLEDs) for the first time.

Phosphorylation of threonine residues on Shc promotes ligand binding and mediates crosstalk between MAPK and Akt pathways in breast cancer cells

Scaffold proteins play important roles in regulating signalling network fidelity, the absence of which is often the basis for diseases such as cancer. In the present work, we show that the prototypical scaffold protein Shc is phosphorylated by the extracellular signal-regulated kinase, Erk. In addition, Shc threonine phosphorylation is specifically up-regulated in two selected triple-negative breast cancer (TNBC) cell lines. To explore how Erk-mediated threonine phosphorylation on Shc might play a role in the dysregulation of signalling events, we investigated how Shc affects pathways downstream of EGF receptor. Using an in vitro model and biophysical analysis, we show that Shc threonine phosphorylation is responsible for elevated Akt and Erk signalling, potentially through the recruitment of the 14-3-3 ζ and Pin-1 proteins.

Hepatic Portal Venous Gas in a Patient with Penetrating Injuries

Hepatic portal venous gas (HPVG) refers to the branching area of low attenuation extending to within 2 cm of the liver capsule in computed tomography scan. The most common causes of HPVG are mesenteric ischaemia in adults and necrotising enterocolitis in infants. HPVG in trauma patients is mostly reported in cases of blunt abdominal trauma. We present a deceased patient who had chest and abdominal wall penetrating injuries with concomitant hypovolemic shock. A computed tomography scan revealed HPVG and pulmonary artery air emboli. The mechanism of the presentation of HPVG in this patient and the possible cause of death would be discussed. (Hong Kong j.emerg.med. 2013;20:382-384)

[Effect and mechanism of silibinin on the inhibition of ALK positive NSCLC cells by sensitizing crizotinib]

Objective: To explore the synergistic effect of silibinin combined with crizotinib on anaplastic lymphoma kinase positive (ALK+ ) non-small cell lung cancer (NSCLC) cells and its mechanism. Methods: H2228 and H3122 cells were treated with silibinin, crizotinib alone or in combination. Cell proliferation was measured by 3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay and colony formation assay. Migration or invasion ability was tested by wound healing assay or transwell assay, respectively. Expressions of E-Cadherin and vimentin protein were examined by immunofluorescence staining. The protein expressions of ALK, p-ALK, E-Cadherin and Vimentin were detected by western blotting.The anti-cancer effect of silibinin combined with crizotinib in vivo was determined by subcutaneously injecting 2×10(6) H2228 cells into immunodeficient nude mice. Results: The result of MTT assay showed that the cell viability of H2228 or H3122 treated with 100 μmol/L silibinin was (88.38±4.10)% or (72.27±3.62)%, respectively, marginally decreased compared with that of the control. The 50% inhibitory concentration (IC(50)) of H2228 cells treated with crizotinib alone or combined with 100 μmol/L silibinin was (917.10±7.75) nmol/L or (238.73±7.67) nmol/L, respectively. The IC(50) of H3122 cells treated with crizotinib alone or combined with 100 μmol/L silibinin was (472.50±15.70) nmol/L or (206.10±12.01) nmol/L, respectively. The IC(50s) of H2228 and H3122 cells were significantly decreased by combined treatment of crizotinib and silibinin compared to crizotinib treatment alone (P<0.01). When compared with the control group, colony forming ratios of H2228 cells were (83.34±2.72)% in 100 μmol/L silibinin treatment group, (69.42±3.06)% in 400 nmol/L crizotinib treatment group and (27.32±1.42)% in combined treatment group. When compared with the control group, colony forming ratios of H3122 cells were (84.45±5.67)% in 100 μmol/L silibinin treatment group, (45.02±5.83)% in 400 nmol/L crizotinib treatment group and (17.43±3.83)% in combined treatment group. Silibinin combined with crizotinib treatment significantly inhibited the colony formation ability of H2228 and H3122 cells (P<0.01). Migration and invasion results showed that combined treatment of crizotinib and silibinin markedly inhibited the migration and invasion ability of H2228 cells (P<0.01). Western blot results indicated that treated with silibinin alone or in combination of crozitinib for 48 hours, the protein level of E-cadherin in H2228 cells was upregulated, while the expressions of p-ALK and vimentin were downregulated, without obvious alteration of ALK protein expression. In the xenograft model, the mean tumor weight was (9.40±2.58)g in crizotinib treatment group and (4.58±1.07)g in the combined treatment group. The inhibitory effect of tumor growth in vivo of combined treatment was significantly superior to that of crizotinib treatment alone (P<0.05). Conclusion: Silibinin enhances the inhibitory effect of crizotinib on ALK positive NSCLC cells, which may be associated with suppression of ALK activity and mesenchymal-epithelial transition.

Severe hypoglycemia and hip fracture in patients with type 2 diabetes: a nationwide population-based cohort study

Hypoglycemia is a major concern in glycemic control. Using the Taiwan National Health Insurance Research Database, we found that the risk of hip fracture was associated with emergency or hospitalization visits of severe hypoglycemia in patients with type 2 diabetes; greater visits were associated with higher incidence of hip fracture.

INTRODUCTION

The objective of the study was to assess the risk of hip fracture among patients with type 2 diabetes mellitus (T2DM) and severe hypoglycemia.

METHODS

Using the National Health Insurance Research database in Taiwan, we identified 2588 patients with T2DM who had developed severe hypoglycemia from 2001 to 2009. A comparison cohort who had never developed severe hypoglycemia was frequency matched at a ratio of approximately 1:2. Multivariate Cox proportional hazard regression analysis was used to evaluate the risk of hip fracture.

RESULTS

During a median follow-up period of 3.9 years, there were 219 hip fracture events in 5173 comparison cohorts and 148 hip fracture events in 2588 hypoglycemia cohorts. The incidence of hip fracture was higher in patients with severe hypoglycemia than without severe hypoglycemia (17.19 vs. 8.83 per 1000 person-years; adjusted HR 1.71, 95% CI = 1.35-2.16). Approximately half of the individuals developed hip fracture within 2 years from the first occurrence of severe hypoglycemia. There was a significant associated trend towards increased hip fracture risk with increasing average visit of severe hypoglycemia per year (p for trend <0.001). Medication analysis showed that patients taking sulfonylurea alone, insulin alone, and insulin secretagogues combined with insulin had a higher associated risk to develop hip fracture.

CONCLUSIONS

Severe hypoglycemia was associated with a higher risk to develop hip fracture. The more the visits of severe hypoglycemia per year indicated the higher associated risk in patients with T2DM. Fall is likely an important reason for severe hypoglycemia in relation to increased risk of hip fracture.

Efficient and Stable Luminescence from Mn2+ in Core and Core-Isocrystalline Shell CsPbCl3 Perovskite Nanocrystals

There has been a growing interest in applying CsPbX₃ (X = Cl, Br, I) nanocrystals (NCs) for optoelectronic application. However, research on doping of this new class of promising NCs with optically active and/or magnetic transition metal ions is still limited. Here we report a facile room temperature method for Mn²⁺ doping into CsPbCl₃ NCs. By addition of a small amount of concentrated HCl acid to a clear solution containing Mn²⁺, Cs⁺, and Pb²⁺ precursors, Mn²⁺-doped CsPbCl₃ NCs with strong orange luminescence of Mn²⁺ at ∼600 nm are obtained. Mn²⁺-doped CsPbCl₃ NCs show the characteristic cubic phase structure very similar to the undoped counterpart, indicating that the nucleation and growth mechanism are not significantly modified for the doping concentrations realized (0.1 at. % - 2.1 at. %). To enhance the Mn²⁺ emission intensity and to improve the stability of the doped NCs, isocrystalline shell growth was applied. Growth of an undoped CsPbCl₃ shell greatly enhanced the emission intensity of Mn²⁺ and resulted in lengthening the radiative lifetime of the Mn²⁺ emission to 1.4 ms. The core-shell NCs also show superior thermal stability and no thermal degradation up to at least 110 °C, which is important in applications.

Luminescent manganese-doped CsPbCl3 perovskite quantum dots

Nanocrystalline cesium lead halide perovskites (CsPbX₃, X = Cl, Br, and I) form an exciting new class of semiconductor materials showing quantum confinement. The emission color can be tuned over the full visible spectral region making them promising for light‒emitting applications. Further control over the optical and magnetic properties of quantum dots (QDs) can be achieved through doping of transition metal (TM) ions such as Mn²⁺ or Co²⁺. Here we demonstrate how, following QD synthesis in the presence of a Mn‒precursor, dropwise addition of silicon tetrachloride (SiCl₄) to the QDs in toluene results in the formation of Mn‒doped CsPbCl₃ QDs showing bright orange Mn²⁺ emission around 600 nm. Evidence for successful doping is provided by excitation spectra of the Mn²⁺ emission, with all features of the CsPbCl₃ QD absorption spectrum and a decrease of the 410 nm excitonic emission life time with increasing Mn‒concentration, giving evidence for enhanced exciton to Mn²⁺ energy transfer. As a doping mechanism we propose a combination of surface etching and reconstruction and diffusion doping. The presently reported approach provides a promising avenue for doping TM ions into perovskites QDs enabling a wider control over optical and magnetic properties for this new class of QDs.

Accuracy and Trending of Continuous Noninvasive Hemoglobin Monitoring in Patients Undergoing Liver Transplantation

BACKGROUND

Shift in large fluid volumes and massive blood loss during liver transplantation frequently leads to rapid changes in hemoglobin (Hb) concentration; thus, to ensure adequate tissue oxygenation, accurate and rapid determination of Hb concentration is essential in transplant recipients. The Radical-7 Pulse CO-Oximeter provides a noninvasive and continuous way to monitor Hb concentration (SpHb) in real time and is an ideal candidate for use during liver transplantation. In this study, we assessed the relationship between SpHb and total Hb (tHb) obtained from arterial blood samples during surgery.

METHODS

Forty patients undergoing liver transplantation were enrolled in this study. tHb and time-matched SpHb were measured at 5 different phases throughout surgery. Paired SpHb and tHb levels were assessed using linear regression, Bland-Altman analysis, and the Critchley polar plot method.

RESULTS

A total of 161 paired measurements with sufficient signal quality were analyzed. The correlation between SpHb and tHb was 0.59 (P < .001). Bland-Altman analysis revealed that a bias between SpHb and tHb was 2.28 g/dL, and limits of agreement (LoA) were from -0.78 to 5.34 g/dL. Trending analysis showed that 87% of data were located within the acceptable trending area, indicating that the trending ability was not satisfied.

CONCLUSIONS

The Radical-7 Pulse CO-Oximeter was not sufficient to monitor Hb levels and trends during liver transplantation surgery in our cohort. In particular, in critical patients and in those with low Hb levels, invasive Hb measurement should be used for assessment.

Emitting-tunable Eu(2+/3+)-doped Ca(8−x)La(2+x) (PO4)6−x(SiO4)xO2 apatite phosphor for n-UV WLEDs with high-color-rendering

A colorful phosphor [Ca_8−xLa_2+x(PO₄)_6−x(SiO₄)_xO₂:Eu²⁺/Eu³⁺] was designed by cosubstituting [Ca²⁺–P⁵⁺] for [La³⁺–Si⁴⁺] for pc-WLEDs with a high CRI.

UV/VUV switch-driven color-reversal effect for Tb-activated phosphors

The remarkable narrow-band emission of trivalent lanthanide-doped phosphors excited by the vacuum ultraviolet (VUV) radiation lines of Xe atoms/Xe₂ molecules at 147/172 nm are extensively investigated in the development of plasma display panels and Hg-free fluorescent lamps, which are frequently used in our daily lives. Numerous solid materials, particularly Tb³⁺-doped oxides, such as silicates, phosphates and borates, are efficient green/blue sources with color-tunable properties. The excitation wavelength and rare earth concentration are usually varied to optimize efficiency and the luminescent properties. However, some underlying mechanisms for the shift in the emission colors remain unclear. The present study shows that a UV/VUV switch systematically controls the change in the phosphor (Ba₃Si₆O₁₂N₂:Tb) photoluminescence from green to blue, resulting in a green emission when the system is excited with UV radiation. However, a blue color is observed when the radiation wavelength shifts to the VUV region. Thus, a configurational coordinate model is proposed for the color-reversal effect. In this model, the dominant radiative decay results in a green emission under low-energy UV excitation from the ⁵D₄ state of the f-f inner-shell transition in the Tb system. However, under high-energy VUV excitation, the state switches into the ⁵D₃ state, which exhibits a blue emission. This mechanism is expected to be generally applicable to Tb-doped phosphors and useful in adjusting the optical properties against well-known cross-relaxation processes by varying the ratio of the green/blue contributions.

Energy transfer induced improvement of luminescent efficiency and thermal stability in phosphate phosphor

Ce3+ and Eu2+/Tb3+/Mn2+ ions codoped Ca6BaP4O17 (CBPO) phosphors have been prepared via a high-temperature solid state reaction. The structural refinement indicates that the as-prepared phosphors crystallize in monoclinic phase (C2/m) and there are two Ca sites and one Ba site in host lattice. The doping ions are determined to occupy Ca sites and the emission of Ce3+ and Eu2+ ions at different Ca sites were identified and discussed. Since bright blue and yellow emissions were observed from Ce3+and Eu2+ ions monodoped CBPO under n-UV excitation, respectively. They were codoped into the CBPO for designing energy transfer from Ce3+ to Eu2+ to improve the luminescence efficiency of Eu2+. In addition, Tb3+ ions were added into the CBPO:Ce3+ system for realizing highly efficient green emission. The energy transfer mechanisms from Ce3+ to Eu2+/Tb3+ ions were discussed. Interestingly, the incorporation of Mn2+ ions into the CBPO:Ce3+ system enhanced the blue emission of Ce3+ ions due to the modification of crystal lattice. Finally, the thermal stability of CBPO:Ce3+, Eu2+/Tb3+/Mn2+ phosphors were investigated systematically and corresponding mechanisms were proposed. Based on these results, the as-prepared CBPO:Ce3+, Eu2+/Tb3+/Mn2+ phosphors can act as potential blue, yellow, green, and emission-tunable phosphors for n-UV based white LEDs.

Critical Red Components for Next-Generation White LEDs

Warm white LEDs with a high color rendering index and a low correlated color temperature have undergone rapid development. In this regard, red-emitting materials-such as fluoride phosphors, namely, A2MF6:Mn(4+) (A = K, Na, and Cs; M = Si, Ge, Zr, Sn, and Ti) and XSiF6:Mn(4+) (X = Ba or Zn), nitridoaluminate phosphor (Sr[LiAl3N4]:Eu(2+)), and nanocrystals of cesium lead iodide perovskite (CsPbI3)-have been extensively investigated recently. These compounds generate narrow emissions in the visible red spectral region that are highly perceived by the human eye and lead to excellent chromatic saturation of the red spectra. This paper describes the structure, luminescence properties, morphologies, thermal features, and moisture resistance of critical red components, as well as their limitations for practical applications. This Perspective also provides a basis for future development and scientific challenges in optical research.

Controllable Eu valence for photoluminescence tuning in apatite-typed phosphors by the cation cosubstitution effect

A schematic presentation for the valence transition from 3+ to 2+ of Eu in Ca_2(1+x)La_8(1−x)(SiO₄)_6−x(PO₄)_xO₂:Eu (0 ≤ x ≤ 6) based on the XANES spectroscopy analysis.

Structural evolution induced preferential occupancy of designated cation sites by Eu2+ in M5(Si3O9)2 (M = Sr, Ba, Y, Mn) phosphors

A schematic presentation for the unexpected blue-shifted luminescence of Eu²⁺ in M₅(Si₃O₉)₂ (M = Sr, Ba, Y, Eu, Mn) based on the preferential occupancy at the designated cation sites.

Biocompatibility of a fish scale-derived artificial cornea: Cytotoxicity, cellular adhesion and phenotype, and in vivo immunogenicity

PURPOSE

To determine whether a fish scale-derived collagen matrix (FSCM) meets the basic criteria to serve as an artificial cornea, as determined with in vitro and in vivo tests.

METHODS

Primary corneal epithelial and stromal cells were obtained from human donor corneas and used to examine the (in)direct cytotoxicity effects of the scaffold. Cytotoxicity was assessed by an MTT assay, while cellular proliferation, corneal cell phenotype and adhesion markers were assessed using an EdU-assay and immunofluorescence. For in vivo-testing, FSCMs were implanted subcutaneously in rats. Ologen(®) Collagen Matrices were used as controls. A second implant was implanted as an immunological challenge. The FSCM was implanted in a corneal pocket of seven New Zealand White rabbits, and compared to sham surgery.

RESULTS

The FSCM was used as a scaffold to grow corneal epithelial and stromal cells, and displayed no cytotoxicity to these cells. Corneal epithelial cells displayed their normal phenotypical markers (CK3/12 and E-cadherin), as well as cell-matrix adhesion molecules: integrin-α6 and β4, laminin 332, and hemi-desmosomes. Corneal stromal cells similarly expressed adhesion molecules (integrin-α6 and β1). A subcutaneous implant of the FSCM in rats did not induce inflammation or sensitization; the response was comparable to the response against the Ologen(®) Collagen Matrix. Implantation of the FSCM in a corneal stromal pocket in rabbits led to a transparent cornea, healthy epithelium, and, on histology, hardly any infiltrating immune cells.

CONCLUSION

The FSCM allows excellent cell growth, is not immunogenic and is well-tolerated in the cornea, and thus meets the basic criteria to serve as a scaffold to reconstitute the cornea.

Photoluminescent Evolution Induced by Structural Transformation Through Thermal Treating in the Red Narrow-Band Phosphor K₂GeF₆:Mn⁴⁺

This study explored optimal preparation conditions for K2GeF6:Mn(4+) red phosphors by using chemical coprecipitation method. The prepared hexagonal P3̅m1 K2GeF6:Mn(4+) exhibited efficient red emission, high color purity, good Mn(4+) concentration stability, and low thermal quenching. Structural evolution from hexagonal P3̅m1 to P63mc and then P63mc to cubic Fm3m occurred after thermal treatment at approximately 400 and 500 °C, respectively. Hexagonal P63mc phase showed an obvious zero phonon line peak at 621 nm, whereas cubic Fm3m phase showed no red emission. Yellowish K2GeF6:Mn(4+) with both hexagonal P3̅m1 and P63mc symmetries are promising commercial red phosphors for white light-emitting diodes.

A Conceptual Framework for the Progression of Balance Exercises in Persons with Balance and Vestibular Disorders

There is little information in peer-reviewed literature to specifically guide the choice of exercise for persons with balance and vestibular disorders. The purpose of this study is to provide a rationale for the establishment of a progression framework and propose a logical sequence in progressing balance exercises for persons with vestibular disorders. Our preliminary conceptual framework was developed by a multidisciplinary team of physical therapists and engineers with extensive experience with people with vestibular disorders. Balance exercises are grouped into six different categories: static standing, compliant surface, weight shifting, modified center of gravity, gait, and vestibulo-ocular reflex (VOR). Through a systematized literature review, interviews and focus group discussions with physical therapists and postural control experts, and pilot studies involving repeated trials of each exercise, exercise progressions for each category were developed and ranked in order of degree of difficulty. Clinical expertise and experience guided decision making for the exercise progressions. Hundreds of exercise combinations were discussed and research is ongoing to validate the hypothesized rankings. The six exercise categories can be incorporated into a balance training program and the framework for exercise progression can be used to guide less experienced practitioners in the development of a balance program. It may also assist clinicians and researchers to design, develop, and progress interventions within a treatment plan of care, or within clinical trials. A structured exercise framework has the potential to maximize postural control, decrease symptoms of dizziness/visual vertigo, and provide "rules" for exercise progression for persons with vestibular disorders. The conceptual framework may also be applicable to persons with other balance-related issues.

Can aspirin reduce the risk of colorectal cancer in people with diabetes? A population-based cohort study

AIM

To evaluate whether aspirin can reduce the risk of colorectal cancer in people with diabetes.

METHODS

We studied ≥ 30-year-old people with diabetes, included in the Longitudinal Health Insurance Database 2005 in Taiwan, who were treated with hypoglycaemic drugs. We used a time-varying Cox regression model to adjust for immortal time bias and to estimate the adjusted hazard ratio and 95% CI for the association between aspirin use and colorectal cancer occurrence.

RESULTS

We studied a total of 60 828 people with diabetes (31 176 men and 29 652 women). Their mean (sd) age was 58.72 (13.33) years. A total of 26 494 people were taking aspirin. Aspirin use 3-5 times/week (moderate frequency) for > 5 years (long duration) was found to reduce the risk of colorectal cancer by 46% (hazard ratio 0.54, 95% CI 0.34-0.86). Aspirin use > 5 times/week (high frequency) for 4-5 years (moderate duration) and > 5 years reduced the risk of colorectal cancer by 56 and 68%, respectively (hazard ratio 0.44, 95% CI 0.24-0.80; hazard ratio 0.32, 95% CI 0.20-0.50). Low frequency (≤ 2 times/week) and/or short duration (≤ 3 years) of aspirin use did not reduce the risk of colorectal cancer.

CONCLUSIONS

Aspirin use with high frequency and long duration reduced the risk of colorectal cancer in people with diabetes in a frequency- and duration-dependent manner, whereas low frequency and/or short duration of aspirin use did not. The dosage, frequency and duration of aspirin use that are sufficient to prevent the incidence of colorectal cancer in people with diabetes require further study.

An increase of curdlan productivity by integration of carbon/nitrogen sources control and sequencing dual fed-batch fermentors operation

Curdlan is produced by Agrobacterium sp. ATCC 31749 under nitrogen-limited conditions not associated with cell growth. A novel curdlan production process was developed based on the different nutrient requirements for microbial cell growth and its efficiency was increased by integrating carbon/nitrogen sources control and sequencing dual fed-batch fermentors operation. By feeding ammonium solution to supply abundant nitrogen source and controlling pH in Fermentor I, cell growth was accelerated. High cell density of 29 g/L was attained. The culture broth in Fermentor I was then inoculated into sequencing Fermentor II which alleviated the high requirement for dissolved oxygen and accumulation of inhibitory metabolic by-products during curdlan production. Fermentor I promoted cell growth. Curdlan production started instantaneously in Fermentor II. By feeding nutrient solution with high carbon/nitrogen ratio and NaOH solution for pH adjustment, a feasible and optimal curdlan production process was formulated. The productivity, conversion efficiency and curdlan yield were achieved of 0.98 g/(L h), 57% (w) and 67 g/L, respectively. Such novel process can be scaled up for significant cost reduction at the industrial level.

Emission-tunable CuInS2/ZnS quantum dots: structure, optical properties, and application in white light-emitting diodes with high color rendering index

Synthesis and application of CuInS2/ZnS core/shell quantum dots (QDs) with varying [Cu]/[In] ratios were conducted using a stepwise solvothermal route. CuInS2 (CIS) core QDs with varying [Cu]/[In] ratios exhibited deep-red emissions result from donor-acceptor pair recombination. The absorption and emission band gap of the CuInS2 QDs increased with the decrease in Cu content. The emission bands of the CuInS2/ZnS were tuned from 550 to 616 nm by controlling the [Cu]/[In] ratio after coating ZnS layer. The CIS QDs model was developed to elucidate the synthesized crystal structure and photoluminescence of the QDs with various [Cu]/[In] ratios. Temperature-dependent photoluminescence spectra of the CIS/ZnS QDs were also investigated. The temperature dependency of the photoluminescence energy and intensity for various CIS/ZnS QDs were studied from 25 to 200 °C. Efficient white light-emitting diodes with high color rendering index values (Ra = 90) were fabricated using CIS/ZnS QDs as color converters in combination with green light-emitting Ba2SiO4:Eu(2+) phosphors and blue light-emitting diodes.

All-in-one light-tunable borated phosphors with chemical and luminescence dynamical control resolution

Single-composition white-emitting phosphors with superior intrinsic properties upon excitation by ultraviolet light-emitting diodes are important constituents of next-generation light sources. Borate-based phosphors, such as NaSrBO3:Ce(3+) and NaCaBO3:Ce(3+), have stronger absorptions in the near-ultraviolet region as well as better chemical/physical stability than oxides. Energy transfer effects from sensitizer to activator caused by rare-earth ions are mainly found in the obtained photoluminescence spectra and lifetime. The interactive mechanisms of multiple dopants are ambiguous in most cases. We adjust the doping concentration in NaSrBO3:RE (RE = Ce(3+), Tb(3+), Mn(2+)) to study the energy transfer effects of Ce(3+) to Tb(3+) and Mn(2+) by comparing the experimental data and theoretical calculation. The vacuum-ultraviolet experimental determination of the electronic energy levels for Ce(3+) and Tb(3+) in the borate host regarding the 4f-5d and 4f-4f configurations are described. Evaluation of the Ce(3+)/Mn(2+) intensity ratios as a function of Mn(2+) concentration is based on the analysis of the luminescence dynamical process and fluorescence lifetime measurements. The results closely agree with those directly obtained from the emission spectra. Density functional calculations are performed using the generalized gradient approximation plus an on-site Coulombic interaction correction scheme to investigate the forbidden mechanism of interatomic energy transfer between the NaSrBO3:Ce(3+) and NaSrBO3:Eu(2+) systems. Results indicate that the NaSrBO3:Ce(3+), Tb(3+), and Mn(2+) phosphors can be used as a novel white-emitting component of UV radiation-excited devices.

Loss of speech after living-related donor liver transplantation: detection of the lesion by diffusion tensor image

INTRODUCTION

Loss of speech after living-related liver transplantation is uncommon. Either immunosuppressive agents, related sequelae, or a neurological event may cause it.

CASE REPORT

A 46-year-old man developed dysarthria and dysphagia on the 10th day after living-related donor liver transplantation for alcoholic cirrhosis with Child-Pugh class C. Brain magnetic resonance images and electroencephalograms could not detect any lesion, but the diffusion tensor image showed a subacute lacunar infarction at right midbrain. The patient's speech improved 1 month after rehabilitation.

CONCLUSIONS

Some unexpected neurological events, such as loss of speech, may occur after liver transplantation. The differential diagnosis becomes very important before active treatment. Magnetic resonance imaging supplemented with diffusion tensor imaging is an effective imaging study in establishing the diagnosis.