An Area- and Energy-Efficient Spiking Neural Network With Spike-Time-Dependent Plasticity Realized With SRAM Processing-in-Memory Macro and On-Chip Unsupervised Learning

In this article, we present a spiking neural network (SNN) based on both SRAM processing-in-memory (PIM) macro and on-chip unsupervised learning with Spike-Time-Dependent Plasticity (STDP). Co-design of algorithm and hardware for hardware-friendly SNN and efficient STDP-based learning methodology is used to improve area and energy efficiency. The proposed macro utilizes charge sharing of capacitors to perform fully parallel Reconfigurable Multi-bit PIM Multiply-Accumulate (RMPMA) operations. A thermometer-coded Programmable High-precision PIM Threshold Generator (PHPTG) is designed to achieve low differential non-linearity (DNL) and high linearity. In the macro, each column of PIM cells and a comparator act as a neuron to accumulate membrane potential and fire spikes. A simplified Winner Takes All (WTA) mechanism is used in the proposed hardware-friendly architecture. By combining the hardware-friendly STDP algorithm as well as the parallel Word Lines (WLs) and Processing Bit Lines (PBLs), we realize unsupervised learning and recognize the Modified National Institute of Standards and Technology (MNIST) dataset. The chip for the hardware implementation was fabricated with a 55 nm CMOS process. The measurement shows that the chip achieves a learning efficiency of 0.47 nJ/pixel, with a learning energy efficiency of 70.38 TOPS/W. This work paves a pathway for the on-chip learning algorithm in PIM with lower power consumption and fewer hardware resources.

Apolipoprotein A-IV restrains fat accumulation in skeletal and myocardial muscles by inhibiting lipogenesis and activating PI3K-AKT signalling

BACKGROUND

One of the pathological characteristics of obesity is fat accumulation of skeletal muscles (SKM) and the myocardium, involving mechanisms of insulin resistance and abnormal lipid metabolism. Apolipoprotein A-IV (ApoA-IV) is an essential gene in both glucose and lipid metabolisms.

MATERIALS AND METHODS

Using high-fat diet (HFD) induced obese apoA-IV-knockout mice and subsequent introduction of exogenous recombinant-ApoA-IV protein and adeno-associated virus (AAV)-transformed apoA-IV, we examined lipid metabolism indicators of SKM and the myocardium, which include triglyceride (TG) content, RT-PCR for lipogenic indicators and western blotting for AKT phosphorylation. Similarly, we used high-glucose-fed or palmitate (Pal)-induced C2C12 cells co-cultured with ApoA-IV protein to evaluate glucose uptake, the phosphoinositide 3-kinase (PI3K)-AKT pathway, and lipid metabolisms.

RESULTS

In stable obese animal models, we find ApoA-IV-knockout mice show elevated TG content, enhanced expression of lipogenic enzymes and diminished phosphorylated AKT in SKM and the myocardium, but both stable hepatic expression of AAV-apoA-IV and brief ApoA-IV protein administration suppress lipogenesis and promote AKT phosphorylation. In a myoblast cell line C2C12, ApoA-IV protein suppresses Pal-induced lipid accumulation and lipogenesis but enhances AKT activation and glucose uptake, and the effect is abolished by a PI3K inhibitor.

CONCLUSION

We find that ApoA-IV reduces fat accumulation by suppressing lipogenesis and improves glucose uptake in SKM and the myocardium by regulating the PI3K-AKT pathway.

Apolipoprotein A-IV reduced metabolic inflammation in white adipose tissue by inhibiting IKK and JNK signaling in adipocytes

Apolipoprotein A-IV (ApoA-IV) plays a role in satiation and serum lipid transport. In diet-induced obesity (DIO) C57BL/6J mice, ApoA-IV deficiency induced in ApoA-IV-/-knock-out (KO mice) resulted in increased bodyweight, insulin resistance (IR) and plasma free fatty acid (FFA), which was partially reversed by stable ApoA-IV-green fluorescent protein (KO-A4-GFP) transfection in KO mice. DIO KO mice exhibited increased M1 macrophages in epididymal white adipose tissue (eWAT) as well as in the blood. Based on RNA-sequencing analyses, cytokine-cytokine receptor interactions, T cell and B cell receptors, and especially IL-17 and TNF-α, were up-regulated in eWAT of DIO ApoA-IV KO compared with WT mice. Supplemented ApoA-IV suppressed lipopolysaccharide (LPS)-induced IKK and JNK phosphorylation in Raw264.7 macrophage cell culture assays. When the culture medium was supplemented to 3T3-L1 adipocytes they exhibited an increased sensitivity to insulin. ApoA-IV protects against obesity-associated metabolic inflammation mainly through suppression in M1 macrophages of eWAT, IL17-IKK and IL17-JNK activity.

[Retrospective analysis of short-term curative effect of total laparoscopic loop ileostomy reversal after radical resection of rectal cancer]

Objective: To investigate the safety, feasibility and short-term efficacy of total laparoscopic loop ileostomy reversal in patients after resection of rectal cancer. Methods: The clinical data of 20 patients who underwent total laparoscopic loop ileoscopic loop ileostomy after radical resection of rectal cancer at Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, or Beijing Chaoyang District Sanhuan Cancer Hospital from October 2019 to June 2020 were collected and retrospectively analyzed. Results: All patients had successfully underwent total laparoscopic ileostomy reversal without conversion to open surgery or discontinued operation. No perioperative related death cases were found. In the whole group, the median operation time was 97 (60-145) minutes and the median intraoperative blood loss was 20 (10-100) milliliters. The median Visual Analogue Scale (VAS) score was 1.9 (1-5) one day after the operation. Nobody needed to use additional analgesic drugs. The median time to grand activities was 25 (16-42) hours, the median time to flatus was 44 (19-51) hours, and the median hospitalization after operation was 6.9 (5-9) days. No patients underwent operation related complications such as operative incision infection, abdominal and pelvic infection, intestinal obstruction, anastomotic leakage, bleeding and so on. Conclusions: Total laparoscopic loop ileostomy reversal appears to be safe, feasible and with promising efficacy for selected patients.

Single-cell RNA sequencing reveals a novel inhibitory effect of ApoA4 on NAFL mediated by liver-specific subsets of myeloid cells

The liver immune microenvironment is a key element in the development of hepatic inflammation in NAFLD. ApoA4 deficiency increases the hepatic lipid burden, insulin resistance, and metabolic inflammation. However, the effect of ApoA4 on liver immune cells and the precise immune cell subsets that exacerbate fatty liver remain elusive. The aim of this study was to profile the hepatic immune cells affected by ApoA4 in NAFL. We performed scRNA-seq on liver immune cells from WT and ApoA4-deficient mice administered a high-fat diet. Immunostaining and qRT-PCR analysis were used to validate the results of scRNA-seq. We identified 10 discrete immune cell populations comprising macrophages, DCs, granulocytes, B, T and NK&NKT cells and characterized their subsets, gene expression profiles, and functional modules. ApoA4 deficiency led to significant increases in the abundance of specific subsets, including inflammatory macrophages (2-Mφ-Cxcl9 and 4-Mφ-Cxcl2) and activated granulocytes (0-Gran-Wfdc17). Moreover, ApoA4 deficiency resulted in higher Lgals3, Ctss, Fcgr2b, Spp1, Cxcl2, and Elane levels and lower Nr4a1 levels in hepatic immune cells. These genes were consistent with human NAFLD-associated marker genes linked to disease severity. The expression of NE and IL-1β in granulocytes and macrophages as key ApoA4 targets were validate in the presence or absence of ApoA4 by immunostaining. The scRNA-seq data analyses revealed reprogramming of liver immune cells resulted from ApoA4 deficiency. We uncovered that the emergence of ApoA4-associated immune subsets (namely Cxcl9+ macrophage, Cxcl2+ macrophage and Wfdc17+ granulocyte), pathways, and NAFLD-related marker genes may promote the development of NAFL. These findings may provide novel therapeutic targets for NAFL and the foundations for further studying the effects of ApoA4 on immune cells in various diseases.

Apolipoprotein A4 Restricts Diet-induced Hepatic Steatosis via SREBF1-mediated Lipogenesis and Enhances IRS-PI3K-Akt Signaling

SCOPE

Hepatic steatosis and insulin resistance (IR) are risk factors for many metabolic syndromes such as NAFLD and T2DM. ApoA4 improves glucose hemostasis by increasing glucose-stimulated insulin secretion and glucose uptake via PI3K-Akt activation in adipocytes. However, whether ApoA4 has an effect on hepatic steatosis or IR remains unclear.

METHODS AND RESULTS

ApoA4-knockout (KO) aggravates diet-induced obesity, hepatic steatosis and IR in mice promoted by increased hepatic lipogenesis gene expression based on RNA-seq data. Conversely, liver-specific overexpression of ApoA4 via AAV-ApoA4 transduction reverses the effect in ApoA4-KO mice, accompanied by suppressed hepatic lipogenesis, increased lipolysis, and fatty acid oxidation. Short-term treatment with recombinant ApoA4 protein improves glucose clearance and liver insulin sensitivity, and reduces hepatic lipogenesis gene expression in the absence of insulin. Moreover, in primary hepatocytes and a hepatic cell line, ApoA4 improves hepatic glucose uptake via IRS-PI3K-Akt signaling and decreases fat deposition and hepatic lipogenesis gene expression by inhibiting SREBF1 activity.

CONCLUSION

ApoA4 restricts hepatic steatosis by inhibiting SREBF1-mediated lipogenesis and improves insulin sensitivity and glucose uptake via IRS-PI3K-Akt signaling in the liver. These findings indicate that ApoA4 may serve as a therapeutic target for obesity-associated NAFLD. This article is protected by copyright. All rights reserved.

P4506New indices of arterial stiffness correlates with disease severity and mid-term prognosis in acute decompensated heart failure

Background

Arterial stiffness has been implicated in pathophysiology of heart failure (HF) since it is involved in the ventricular-vascular coupling. Recently, new indices obtained by a cuff oscillometric technique, the arterial velocity-pulse index (AVI) for the stiffness of central arteries and the arterial pressure-volume index (API) for the stiffness of peripheral arteries have been developed and validated. However, the AVI and API measurement has not been attempted in HF population.

Purpose

This study aimed to investigate the relationship between the AVI, API and clinical outcomes in HF patients.

Methods

A prospective cohort of patients with acute decompensated HF were enrolled within 6 months, who were admitted to a tertiary referral hospital in China. Measurement of the AVI and API (AVE-1500, Shisei Datum, Tokyo, Japan) was performed on the day of admission and discharge. Patients were followed up to 6 months for the composite endpoint of all-cause death and HF rehospitalization.

Results

A Total of 127 patients were recruited for analysis (60±15 years, 70% male). 80% of the patients were in New York Heart Association (NYHA) Class III or above at admission, who presented a mean left ventricular ejection fraction (LVEF) of 34±9%. During hospitalization, all patients received guideline directed medical therapy if not contraindicated. The AVI (27.3±5.2 vs. 28.6±6.7, p=0.002) and API (24.9±4.9 vs. 26.0±6.5, p=0.05) were lower at discharge than at admission. By dividing the patients into tertiles according to the amino-terminal pro-brain natriuretic peptide (NT-proBNP), LVEF, transmitral E velocity over mitral annular e' velocity (E/e' ratio) and systolic blood pressure (SBP) at admission, it was observed that the AVI increased with a higher level of NT-proBNP (p for trend <0.001), a larger E/e' (p<0.001) and a lower LVEF (p=0.001), while the API increased as the SBP became higher (p=0.005).The improvement in AVI at discharge was correlated with that in LVEF (R=-0.3024, p<0.05) and NT-proBNP (R=0.3118, p<0.05), while the change in API was positively correlated with that in SBP (R=0.3897, p<0.001). In 6 months after discharge, there were 52 predefined events including 15 deaths and 44 HF rehospitalization. Apart from the level of NT-proBNP, the AVI at discharge of ≥26 showed a trend of being associated with the composite outcome (2.747, 1.411–5.349, p<0.001 for univariate analysis; 1.8648, 0.8928–3.8949, p=0.0973 for multivariate analysis).

Conclusions

New noninvasive arterial stiffness indices as the AVI and API reflected severity of illness and mid-term prognosis in admitted HF patients. Further studies are warranted for understanding its mechanisms and developing clinical applications.

Isolation and characterization of Streptomyces spp. strains F-6 and F-7 capable of decomposing alkali lignin

Biodegradation and bioconversion of lignin are the result of the combined action of fungi, bacteria and actinomycetes. Through screening from forest soil, two novel isolated actinomycete strains were identified as Streptomyces spp. strains F-6 and F-7 by their morphology, cultural characteristics and high homology to the 16S rRNA gene. Both strains possessed laccase and manganese peroxidase activities. Laccase activity produced by strain F-6 was up to 935.4 U g(-1) dry cell weight. More than 50% of alkali lignin was removed by strains F-6 and F-7 in 12 days of incubation. GC-MS analysis of the biodegraded products showed strain F-6 converted lignin into phenol and broken phenol compounds. The two strains could co-culture with white-rot fungus, and the combined actinonycete-fungus system decomposed alkali lignin effectively.

Decolorization of cotton pulp black liquor by pleurotus ostreatus in a bubble-column reactor

Decolorization of cotton pulp black liquor by Pleurotus ostreatus B1 in a bubble-column reactor (BCR) was studied. The optimal conditions for the running of BCR are 30 degrees C, pH 6.0, aeration rate 1.2 L min(-1), and mycelial age 7 days. Under the optimal conditions, the BCR was run for four cycles (each cycle, 12 days) and the same mycelial pellets were reused. The ultimate decolorization and COD removal rates are 76% and 80%, respectively.

[Study on analysis of trace phenol in small amount of aqueous sample by liquid-liquid micro-extraction and gas chromatography]

A method for the liquid-liquid micro-extraction and gas chromatographic analysis of trace phenol in small amount of aqueous sample has been developed. The influences of acid and salts on recovery rate of phenol were examined. And, the influences of injection speeds and the conditions of silica wool in injection port on the quantitation precision were tested. With a direct injection port, an FID and a DB-1 capillary column of wide bore, a detection limit of 1 microgram.L-1 can be obtained employing 8 mL water sample, 160 microL ethyl acetate and 3.5 g ammonium sulfate. The added recoveries were in the range of 95.0%-98.5%. The relative standard deviations were in the range of 2.8%-3.3%. This method is simple, convenient, rapid, accurate and practical.

Characterization of primary isolate-like variants of simian-human immunodeficiency virus

Several different strains of simian-human immunodeficiency virus (SHIV) that contain the envelope glycoproteins of either T-cell-line-adapted (TCLA) strains or primary isolates of human immunodeficiency virus type 1 (HIV-1) are now available. One of the advantages of these chimeric viruses is their application to studies of HIV-1-specific neutralizing antibodies in preclinical AIDS vaccine studies in nonhuman primates. In this regard, an important consideration is the spectrum of antigenic properties exhibited by the different envelope glycoproteins used for SHIV construction. The antigenic properties of six SHIV variants were characterized here in neutralization assays with recombinant soluble CD4 (rsCD4), monoclonal antibodies, and serum samples from SHIV-infected macaques and HIV-1-infected individuals. Neutralization of SHIV variants HXBc2, KU2, 89.6, and 89.6P by autologous and heterologous sera from SHIV-infected macaques was restricted to an extent that these viruses may be considered heterologous to one another in their major neutralization determinants. Little or no variation was seen in the neutralization determinants on SHIV variants 89.6P, 89.6PD, and SHIV-KB9. Neutralization of SHIV HXBc2 by sera from HXBc2-infected macaques could be blocked with autologous V3-loop peptide; this was less true in the case of SHIV 89.6 and sera from SHIV 89.6-infected macaques. The poorly immunogenic but highly conserved epitope for monoclonal antibody IgG1b12 was a target for neutralization on SHIV variants HXBc2, KU2, and 89.6 but not on 89.6P and KB9. The 2G12 epitope was a target for neutralization on all five SHIV variants. SHIV variants KU2, 89.6, 89.6P, 89.6PD, and KB9 exhibited antigenic properties characteristic of primary isolates by being relatively insensitive to neutralization in peripheral blood mononuclear cells with serum samples from HIV-1-infected individuals and 12-fold to 38-fold less sensitive to inhibition with recombinant soluble CD4 than TCLA strains of HIV-1. The utility of nonhuman primate models in AIDS vaccine development is strengthened by the availability of SHIV variants that are heterologous in their neutralization determinants and exhibit antigenic properties shared with primary isolates.

[A gas chromatographic method to decrease the detection limit of trace benzene in CS2 extract]

A method to decrease the detection limit of trace benzene in CS2 extract from coastal water by gas chromatography has been studied. A direct injection port (Shimadzu WBI-17) and a 2 m x 2 mm i.d. column packed with Chromosorb W(AW-DMCS) coated with 10% SE-30 was used. It is simpler and has low detection limit, small sample amount and high repeatability. The experiment showed that the trace water in the organic phase and the too small purge flow of the direct injection port could cause serious tailing of CS2 peak. There was an optimum value of the purge flow (purge flow/total flow = 5%). The minimum detectable limit of benzene was 4 micrograms/L. The repeatability (RSD) was better than 6% and the average recovery was 96.7%.

Neutralizing antibody responses to human immunodeficiency virus type 1 in primary infection and long-term-nonprogressive infection

The role of neutralizing antibodies in human immunodeficiency virus type 1 (HIV-1) infection is poorly understood and was assessed by evaluating responses at different stages of infection. Undiluted sera from long-term nonprogressors (LTNP) had broad neutralizing antibodies against heterologous primary isolates and were more likely to neutralize the contemporaneous autologous isolate than were sera from short-term nonprogressors and progressors. In primary infection, envelope-specific IgG was detected before the initial decline in plasma viremia, but neutralizing antibodies developed more slowly. Here, neutralizing antibodies against strains SF-2 and MN were sometimes the first to be detected, but titers were low for at least 17 weeks from onset of symptoms. Neutralizing antibodies against the early autologous isolate were detected for 4 patients by 5-40 weeks but were undetectable in 2 additional patients for 27-45 weeks. The results indicate that neutralizing antibody responses are slow to develop during primary infection and are uniquely broad in LTNP.

Neutralizing and infection-enhancing antibody responses to human immunodeficiency virus type 1 in long-term nonprogressors

Serum antibodies from human immunodeficiency virus type 1 (HIV-1)-infected long-term non-progressors (LTNPs) and non-LTNPs were evaluated for virus neutralization and infection enhancement in vitro. Sera from LTNPs had higher average titers of neutralizing antibodies to HIV-1 strains IIIB and MN and more frequently neutralized primary isolates from progressors (14.9% vs. 1.3%, P = .002). Replication-competent HIV-1 was isolated from peripheral blood mononuclear cells and lymph nodes of 3 LTNPs. All viruses from LTNPs had a non-syncytium-inducing phenotype, were resistant to neutralization by autologous serum obtained at the time of virus isolation, and showed little evidence of a heightened sensitivity to neutralization by heterologous sera. Complement-mediated, antibody-dependent enhancement (C'-ADE) of HIV-1IIIB and primary isolates was equally prevalent for sera from LTNPs and non-LTNPs. Results indicate that LTNPs produce vigorous serum antibody responses and that long-term nonprogression is not associated with homologous neutralization or the absence of C'-ADE.

Complement control proteins, CD46, CD55, and CD59, as common surface constituents of human and simian immunodeficiency viruses and possible targets for vaccine protection

Complement control proteins include a group of membrane-bound surface antigens that protect cells from complement lysis by preventing formation of the membrane attack complex (MAC) of complement. HIV-1 and SIV are known to possess cellular proteins, making it possible that some of them contribute to the ability of these viruses to evade complement lysis. Three complement control proteins, CD46 (membrane cofactor protein), CD55 (decay accelerating protein), and CD59 (HRF20), were found by flow cytometry to be expressed on the surface of CD4+ cell lines commonly used for HIV-1 and SIV synthesis. Monoclonal antibodies to each of these proteins precipitated HIV-1 IIIB and SIV delta/B670 synthesized in CEM x 174 cells and two primary HIV-1 isolates synthesized in peripheral blood mononuclear cells, indicating that CD46, CD55, and CD59 are physically associated with the virus membrane after the virus has been released from the surface of infected cells. Additional experiments showed that the precipitated material contained infectious virus, confirming that whole virus was precipitated. Evidence that CD46 and CD59 are immunogenic in macaques was found when anti-cell antibodies in plasmas from macaques immunized with human cell-grown SIV blocked anti-CD46 and anti-CD59 from binding to the surface of CEM x 174 cells. Anti-cell antibodies rendered HIV-1 susceptible to complement lysis as measured by the release of p24 core protein, and consistently produced a complement-dependent reduction in HIV-1 and SIV infectivity of 1-3 logs. These results demonstrate that CD46, CD55, and CD59 are common surface constituents of HIV-1 and SIV. The results also raise the possibility that the mechanism of SIV vaccine protection attributed to anti-cell antibodies could have involved complement-mediated virolysis.

Binding of human immunodeficiency virus type 1 to the C3b/C4b receptor CR1 (CD35) and red blood cells in the presence of envelope-specific antibodies and complement. National Institutes of Health AIDS Vaccine Clinical Trials Networks

Immune complexes formed in vitro by incubating cell-free human immunodeficiency virus type 1 (HIV-1) with sera from infected or gp160-vaccinated persons, together with normal human serum as a source of complement, readily bound to K562 cells expressing recombinant human complement receptor type 1 (CR1). However, antibodies from seronegative persons had little or no effect. This effect was absent in the presence of heat-inactivated or C3-depleted normal human sera or when wild type K562 cells were used, confirming a requirement for complement and CR1. In additional experiments, complement alone targeted HIV-1 to CR1 on red blood cells, and envelope-specific antibodies increased this effect. These results demonstrate that envelope-specific antibodies promote HIV-1 immune complex formation with complement and that these complexes readily bind CR1 on cell surfaces.

Role of early afterdepolarization in familial long QTU syndrome and torsade de pointes

Torsade de pointes (TdP) syncopal episodes were almost invariably precipitated by emotional stress or menstruation in a 17-year-old girl. U wave accentuation occurred during sinus rhythm without pauses in periods of heightened sympathetic tone. To examine the role of early afterdepolarization (EAD), monophasic action potentials were recorded during ventricular extrasystoles and TdP occurring spontaneously and induced by ventricular pacing. The effects of lidocaine, verapamil, propranolol, and epinephrine were assessed. Our data show that: (1) EAD plays a significant role in the genesis of familial long QTU syndrome and TdP; (2) rapid ventricular pacing causes postpause-dependent EADs, U waves, and TdP; and (3) EAD is enhanced by epinephrine infusion in the absence of pause, whereas EAD-triggered firing is inhibited by verapamil and propranolol but not by lidocaine.

DNA fragments of Bombyx mori nuclear polyhedrosis virus containing the promoters active in prokaryotes

Using a promoter probe plasmid in E. coli called pHE5, eight different HindIII and one SalI DNA fragments of Bombyx mori nuclear polyhedrosis virus, directing the expression of the tetracycline resistance gene, have been cloned and isolated. The tetracycline resistance levels of the strains containing the recombinant plasmids were measured. Among them, the highest level of the resistance to tetracycline was 30 micrograms/ml. Part of the nucleotide sequence of a DNA fragment was determined. A sequence similar to the E. coli promoter was found.

Hemodynamic findings during sinus rhythm, atrial and AV sequential pacing compared to ventricular pacing in a dog model

The hemodynamic responses of atrial (AP), atrioventricular sequential (AVP) and ventricular pacing (VP) were compared to sinus rhythm (SR) in seventeen anesthetized dogs with intact AV conduction. The atrium and/or ventricle were paced at fixed rates above the control sinus rate. An AV interval shorter than normal conduction was selected to capture the ventricle. The changes of pulmonary capillary wedge pressure (PCWP, mmHg), mean aortic pressure (MAP, mmHg), cardiac output (CO, L/min), systemic vascular resistance (SVR, dynes/s/cm-5), left ventricular stroke work index (SWI) and mean systolic ejection rate (MSER, ml/s) during sinus rhythm, atrial pacing and atrioventricular sequential pacing (expressed in percentages of the individual values during ventricular pacing) were: (Chart: See text) The importance of atrial systole for cardiac performance was clearly demonstrated in dogs with normally compliant hearts. In both atrial and atrioventricular sequential pacing compared to ventricular pacing there was a reduction of pulmonary capillary wedge pressure (PCWP) (p less than 0.01) and systemic vascular resistance (SVR) (p less than 0.01) despite an increase in cardiac output (CO). The lesser mean systolic ejection rate (MSER) found during atrioventricular sequential pacing compared to sinus rhythm and atrial pacing may be explained by the abnormal ventricular depolarization in this pacing mode; nevertheless, the mean systolic ejection rate was still greater than that found during ventricular pacing (p less than 0.05).