Examining failure learning in online lending: Complete failure vs. incomplete failure.

We examine the learning effects of borrowers' failures in online lending. Based on funding ratios of borrowers' loan listings in online lending, we first explore the role of failure degree in borrowers' future funding performance. Further, we disaggregate borrowers' funding failure into complete failure and incomplete failure, and compare theirs learning effects. Using a large sample of 610,000 online loan applications over six years from a Chinese leading online lending platform Renrendai, we use funding ratio to quantifiably measure each loan listing's failure degree and conduct a series of tests. The results show that: (1) Borrowers' failure degree of prior loan applications is negatively associated with one's subsequent funding performance. (2) Borrowers' complete failure cannot promote learning, while incomplete failure is good for future performance. (3) Both incomplete failure and complete failure interacted to influence the value of each type of experience and generate improved learning. Our results are robust across a variety of settings. The study sheds light for deeply understanding of failure learning phenomenon, and can also provide important implications for online lending managers to support successful financial transactions.

Polypharmacy and Utilization of Health Care Services: A Cohort Study of People Aged Over 50 Years in Taiwan.

This study aimed to understand the changes and correlation in the long-term trends of polypharmacy and the utilization of health care services in a population over the age of 50 years through the use of a national database. A total of 2813 subjects who participated in surveys in 1999, 2003, and 2007 were selected as the samples. Each subject was followed-up for the period of 9 years. From 1999 to 2007, the proportion of mild and severe polypharmacy cases increased from 41.5% (1999) to 51.3% (2003) and 57.1% (2007), respectively. This study found that the more severe the polypharmacy was, the higher the risk of health care service utilization would be. The Generalized Estimating Equation model of multivariate analysis showed that the incidence rate ratio of medical utilization increased with the severity of polypharmacy, as did the use of advanced medical resources (ie, the number of hospitalizations). In particular, the increase in incidence rate ratio was more significant in 3 aspects: (1) number of pharmacy visits; (2) number of emergency room admissions; and (3) number of hospitalizations. The government should establish policies and guidance for the safe use of medicines to ensure reduced risk for older people.

Integrin-ß1 regulates chondrocyte proliferation and apoptosis through the upregulation of GIT1 expression.

Chondrocytes play a critical role in the repair process of osteoarthritis, which is also known as degenerative arthritis. Integrins, as the key family of cell surface receptors, are responsible for the regulation of chondrocyte proliferation, differentiation, survival and apoptosis through the recruitment and activation of downstream adaptor proteins. Moreover, G-protein-coupled receptor kinase interacting protein-1 (GIT1) exerts its effects on cell proliferation and migration through interaction with various cytokines. It has been previously suggested that GIT1 acts as a vital protein downstream of the integrin-mediated pathway. In the present study, we investigated the effects of integrin-ß1 on cell proliferation and apoptosis, as well as the underlying mechanisms in chondrocytes in vitro. Following transfection with a vector expressing integrin-ß1, our results revealed that the overexpression of integrin-ß1 enhanced GIT1 expression, whereas the knockdown of integrin-ß1 by siRNA suppressed GIT1 expression. However, no significant effect was observed on integrin-ß1 expression following the enforced overexpression of GIT1, which suggests that GIT1 is localized downstream of integrin-ß1. In other words, integrin-ß1 regulates the expression of GIT1. Furthermore, this study demonstrated that integrin-ß1 and GIT1 increased the expression levels of aggrecan and type II collagen, thus promoting chondrocyte proliferation; however, they inhibited chondrocyte apoptosis. Taken together, our data demonstrate that integrin-ß1 plays a vital role in chondrocyte proliferation, differentiation and apoptosis. GIT1 exerts effects similar to those of integrin-ß1 and is a downstream target of integrin-ß1.

Response surface optimized extraction of 1-deoxynojirimycin from mulberry leaves (Morus alba L.) and preparative separation with resins.

In the present study, the extraction technology and preparative separation of 1-deoxynojirimycin from mulberry leaves were systematically investigated. Four extraction parameters (ethanol concentration, extraction temperature, extraction time and ratio of solvent to sample) were explored by response surface methodology (RSM). The results indicated that the maximal yield of 1-deoxynojirimycin was achieved with an ethanol concentration of 55%, extraction temperature of 80 °C, extraction time of 1.2 h and ratio of solvent to sample of 12:1. The extraction yield under these optimum conditions was found to be 256 mg/100 g dry mulberry leaves. A column packed with a selected resin was used to perform dynamic adsorption and desorption tests to optimize the separation process. The results show that the preparative separation of 1-deoxynojirimycin from mulberry leaves can be easily and effectively done by adopting 732 resin. In conclusion, 732 resin is the most appropriate for the separation of 1-deoxynojirimycin from other components in mulberry leaves extracts, and its adsorption behavior can be described with Langmuir isotherms and a two-step adsorption kinetics model. The recovery and purity of 1-deoxynojirimycin in the final product were 90.51% and 15.3%, respectively.

[Optimization for preparation technology of shangke jiefu lotion by orthogonal test].

OBJECTIVE: To optimize the preparation technology of Shangke Jiefu lotion. METHODS: The extraction process was optimized by orthogonal test, with water addition, extraction times and time used for extraction as factors of investigation. In refined process test, alcohol precipitation concentration, time, and the relative density of extract were studied. Each factor had three levels. The content of sophorcarpidine and the yield of dry extract were used as the evaluation indexes. The content of sophorcarpidine was determined by HPLC, and dry extract rates were determined by drying method. RESULTS: The best extraction condition was as follows: the amount of water was 10 times of the medicinal materials, the decoction duration was 2 h and for 3 times. The optimum purification process was: alcohol precipitation concentration was 50%, time was 15 hours, relative density of extract was 1.05 g/mL. CONCLUSION: The optimized preparation technology of Shangke Jiefu lotion is stable, feasible and convenient. It provides a theoretical basis for standardized production.

[Study on the flax seed enzymatic degumming process by central composite design and response surface method].

OBJECTIVE: To optimize extraction condition of degumming from flax seed by the response surface method. METHODS: The central composite design-response surface method selected the best technology and forecasting analysis with the ratio of material to liquid, sodium chloride dosage, soaks time as the independent variable and flax seed dry rubber weight for the dependent variable, through to the level of the independent variable multiple linear regression and binomial fitting. RESULTS: The optimum process condition was as follows: ratio of liquid to materials was 37:1, sodium chloride dosage was 2 g, soaks time was 120 min. CONCLUSION: The method is simple, reasonable, stable and predictability.

[Electrophysiology of two human hyperpolarization activated cyclic nucleotide-gated potassium channels expressed in HEK293 cells].

OBJECTIVE: To express the human HCN2 and HCN4 genes in HEK293 cells and investigate the electrophysiology of the expressed channel protein. METHODS: cDNA encoding human HCN2 or HCN4 gene was ligated into a shuttle vector pAdTrack-CMV. Homologous recombination was performed in Escherichia coli of the line BJ5183. Human embryonic kidney cells of the line 293 (HEK293 cells) were cultured and transfected with the positive recombinant adenovirus plasmid. Then the HEK293 cells were infected by AdhHCN2 or AdhHCN4 and the whole cell hyperpolarization-activated currents were recorded in HEK293 cells transfected with hHCN2 and hHCN4. RESULTS: If-like currents could be found in the HEK293 cells transfected with hHCN2 and hHCN4. The channels were activated by hyperpolarized potentials. Boltzmann equation showed that the half-activation voltage of the hHCN2 and hHCN4 channels were -114.8 mV +/- 3.3 mV and -125.9 mV +/- 2.9 mV respectively (P = 0.024). The reversal slope factors of the hHCN2 and hHCN4 channels were 11.1 mV +/- 1.2 mV and 13.7 mV +/- 1.3 mV respectively (P = 0.22). The activation kinetics was faster in hHCN2 than in hHCN4, with the activation constants at -110 mV being 0.99 s +/- 0.21 s and 8.47 s +/- 2.85 s respectively. The relative permeation ratio for sodium and potassium were 0.40 and 0.34 respectively in these two channels. Caesium chloride of the concentration of 2 mmol/L prominently inhibited both currents. CONCLUSION: The target genes hHCN2 and hHCN4 are successfully expressed in HEK293 cells, and the expressed functional channels have profoundly different activation kinetics.

[Electrophysiological effects of hyperpolarization activated cyclic nucleotide gated channel 4 overexpression in neonatal cardiomyocytes mediated by recombinant adenovirus].

OBJECTIVE: To explore the electrophysiological effects of hyperpolarization activated cyclic nucleotide gated channel 4 (HCN4) overexpression in rat neonatal cardiomyocytes mediated by recombinant adenovirus. METHODS: Ventricular cardiomyocytes were obtained from 20 neonatal rats. Recombinant adenovirus carrying HCN4 gene, AdHCN4, a dominant isoform of hyperpolarization activated cyclic nucleotide gated cation channel gene in cardiac transduction system, was constructed and used to transfect the neonatal rat ventricular cardiomyocytes. Untransfected cardiomyocytes were used as controls. RT-PCR and immunofluorescence cytochemistry were used to detect the HCN4 mRNA and protein expression. The electrophysiological characteristics of infected cardiomyocytes were studied by patch clamp. RESULTS: The mRNA and protein expression levels of HCN4 in AdHCN4 infected cardiomyocytes were both markedly higher than those of the control cardiomyocytes. AdHCN4 caused a significant increase in The spontaneous rate in the transfected cardiomyocytes was 92.5 + 7.4 bpm, significantly higher than that of the control cells (68.9 + 6.2 bpm, P < 0.05). Patch clamp experiments showed that the pacemaker current density in the AdHCN4 infected cardiomyocytes was 115.7 + 7.8 pA/pF, significantly higher than that of the untransfected cells (7.2 + 0.6 pA/pF, P < 0.05). CONCLUSION: Overexpression of HCN4 can enhance the autorhythmicity of neonatal cardiomyocytes and significantly increase the spontaneous beat rate. HCN4 channel gene may represent a candidate gene in gene therapy for bradycardia diseases.

[Transfecting rat heart with human pacemaker gene in vivo to create a biological pacemaker].

OBJECTIVE: To test the ability and safety of injecting the hHCN gene into the ventricle of intact rats to create a novel biological pacemaker and to explore the duration of the hHCN over-expression in vivo. METHODS: Adenoviral constructs incorporating hHCN4 and green fluorescent protein (GFP) were subepicardially injected into the rats' left ventricular wall in situ (n = 10). Control group was injected with adenoviral constructs of GFP alone (n = 10). ECGs were recorded every day within the initial three days after operation. Up to seven days after injection, all rats were anesthetized and subjected to cervical vagal trunks stimulation to permit the emergence of escape rhythm. Then pace-mapping was performed by the hand-hold electrode. Finally, hearts were removed for histology and immunofluorescence study. RESULTS: Ventricular arrhythmic events were not found during the first three days. During vagal stimulation, the rate of spontaneous rhythm in the hHCN4-injected group was significantly more rapid than that in the control group (69 bpm +/- 6 bpm vs 41 bpm +/- 10 bpm, P < 0.001). Pace-mapping confirmed the escape rhythm in the hHCN4-injected group was originated near the injection site. Immunofluorescence study showed the overexpression of hHCN4 on the site of injection. However, the duration of hHCN overexpression was no more than one month after injection. CONCLUSION: The overexpression of hHCN4 provides ventricular escape rhythm with the physiologically acceptable rate. Long-term feasibility of this approach needs to be tested.