Backward bifurcation of a plant virus dynamics model with nonlinear continuous and impulsive control.

Roguing and elimination of vectors are the most commonly seen biological control strategies regarding the spread of plant viruses. It is practically significant to establish the mathematical models of plant virus transmission and regard the effect of removing infected plants as well as eliminating vector strategies on plant virus eradication. We proposed the mathematical models of plant virus transmission with nonlinear continuous and pulse removal of infected plants and vectors. In terms of the nonlinear continuous control strategy, the threshold values of the existence and stability of multiple equilibria have been provided. Moreover, the conditions for the occurrence of backward bifurcation were also provided. Regarding the nonlinear impulsive control strategy, the stability of the disease-free periodic solution and the threshold of the persistence of the disease were given. With the application of the fixed point theory, the conditions for the existence of forward and backward bifurcations of the model were presented. Our results demonstrated that there was a backward bifurcation phenomenon in continuous systems, and there was also a backward bifurcation phenomenon in impulsive control systems. Moreover, we found that removing healthy plants increased the threshold $ R_{1}. $ Finally, numerical simulation was employed to verify our conclusions.

Research progress on vesicles from Chinese medicinal herbs. / æ¤ç‰©ç±»ä¸­è¯æ¥æºå›Šæ³¡çš„ç ”ç©¶è¿›å±•.

Vesicles derived from Chinese medicinal herbs (VCMH) are nano-vesicular entities released by the cells of Chinese medicinal herbs. VCMHs have various biological effects and targeting characteristics, and their component chemicals and functional activities are closely related to the parent plant. VCMH differs from animal-derived vesicles in three ways: stability, specificity, and safety. There are a number of extraction and isolation techniques for VCMH, each with their own benefits and drawbacks, and there is no unified standard. When two or more approaches are used, high quantities of intact vesicles can be obtained more quickly and efficiently. The obtained VCMHs were systematically examined and evaluated. Firstly, they are generally saucer-shaped, cup-shaped or sphere, with particle size of 10-300 nm. Secondly, they contain lipids, proteins, nucleic acids and other active substances, and these components are an important part for intercellular information transfer. Finally, they mostly have good biocompatibility and low toxicity, with anti-inflammatory, antioxidant, anti-tumor and anti-fibrotic effects. As a new drug carrier, VCMHs have outstanding active targeting capabilities, and the capsule form can effectively preserve the drugs, considerably enhancing drug delivery efficiency and stability in vitro and in vivo. The modification of its vesicular structure by suitable physical or chemical means can further create more stable and precise drug carriers. This article reviews the extraction and purification techniques, activity evaluation and application of VCMH to provide information for further research and application of new active substances and targeted drug carriers.

Peripheral high levels of CRP predict progression from normal cognition to dementia: A systematic review and meta-analysis.

OBJECTIVE: Several cross-sectional studies have demonstrated a relationship between inflammation and dementia. Uncertainty exists over the ability of C-reactive protein (CRP), one of the most investigated markers of inflammation, to predict the progression of normal cognition to dementia. A systematic review and meta-analysis were performed to assess whether high peripheral levels of CRP are associated with cognitive impairment and whether CRP is a risk factor for predicting progression from normal cognition to cognitive decline or dementia. METHODS: Literature published before November 2022 was retrieved from PubMed, Embase, and Web of Science. Prospective cohort studies that employed recognized evaluation instruments to assess global cognitive function or used accepted diagnostic criteria to ascertain dementia were selected. Subgroup analysis was conducted on specific cognitive domains and causes of dementia (i.e., Alzheimer's disease and vascular dementia). Odds ratios (ORs) and hazard ratios (HRs) were extracted and merged to facilitate data analysis. A random-effects model was used for the meta-analysis and a descriptive analysis of the data that could not be merged was conducted. RESULTS: A total of 13 articles (14 cohort studies) were included for meta-analysis and six articles were included for descriptive analysis. The results showed that high CRP levels were not related to future cognitive decline (OR = 1.115; 95 % CI: 0.830-1.497; p = 0.469) but were associated with an increased risk of conversion to dementia. (HR = 1.473; 95 % CI: 1.037-2.090; p = 0.0394). This association persisted after full adjustment for potential covariates, with an OR of 1.044 (95 % CI:0.767-1.421, p = 0.785) for cognitive decline and an HR of 1.429 (95 % CI:1.088-1.876, p = 0.010) for dementia. The subgroup analysis showed that a higher level of CRP was related to a decline in visual-spatial ability (OR = 1.402, 95 % CI: 1.045-1.882, p = 0.024) and the risk of conversion to vascular dementia (total effect size of OR and HR = 2.769, 95 % CI: 1.586-4.83, p = 0.000). CONCLUSIONS: Higher CRP levels as an indicator of chronic systemic inflammation cannot predict future cognitive decline but may indicate a higher risk of conversion to dementia.

Effect of hearing aids on cognitive functions in middle-aged and older adults with hearing loss: A systematic review and meta-analysis.

Objective: The study aimed to examine the effects of hearing aids on cognitive function in middle-aged and older adults with hearing loss. Data sources and study selection: PubMed, Cochrane Library, and Embase were searched for studies published before 30 March 2022. Randomized controlled trials (RCTs) and non-randomized studies of interventions (NRSIs) were included in the search. Restriction was set on neither types, severity, or the time of onset of hearing impairment nor cognitive or psychiatric statuses. Data extraction and synthesis: Two independent reviewers extracted data and assessed the study quality of RCTs. Cognitive function outcomes were descriptively summarized and converted to standardized mean difference (SMD) in the meta-analysis. Meta-analysis was conducted in RCTs. Sub-group analyses were conducted by cognitive statuses, psychiatric disorders, and cognitive domains. Results: A total of 15 studies met the inclusion criteria, including five RCTs (n = 339) and 10 NRSIs (n = 507). Groups were classified as subjects without dementia or with normal global cognition, subjects with AD or dementia, and subjects with depressive symptoms. For subjects without dementia, improvements were found in global cognition, executive function, and episodic memory. For subjects with depressive symptoms, improvements were found in immediate memory, global cognition, and executive function. No improvement was found in subjects with AD or dementia. In total, four RCTs were included in the meta-analysis. For subjects without dementia (SMD = 0.11, 95% confidence interval [CI]: -0.15-0.37) and those with AD, no significant effect was found (SMD = -0.19, 95% CI: -0.65-0.28). For subjects without dementia, no significant effect was found in language (SMD = 0.14, 95% CI: -0.30-0.59) or general executive function (SMD = -0.04, 95% CI: -0.46-0.38). Further sub-group analysis found no significant effect in executive function (SMD = -0.27, 95% CI: -0.72-0.18) or processing speed (SMD = -0.02, 95% CI: -0.49-0.44). Conclusion: Hearing aids might improve cognitive performance in domains such as executive function in subjects without dementia. The effects on subjects with depressive symptoms remained unclear. No improvement was found in subjects with AD or dementia. Long-term RCTs and well-matched comparison-group studies with large sample sizes are warranted. Systematic review registration: https://www.crd.york.ac.uk/PROSPERO/, identifier: CRD42022349057.

First report of Impatiens necrotic spot orthotospovirus infecting Tulbaghia violacia Harv. in China.

Tulbaghia violacea Harv. indigenous to southern African countries, is an herbaceous perennial bulbous plant belonging to the family Amaryllidaceae. It is a popular garden plant in China. This attractive plant is traditionally used as medicine and repellent (Kubec et al. 2002; Moodley et al. 2015). In June 2021, T. violacea plants showing typical tospovirus-like symptoms of chlorotic rings patterns, were found at the campus of Yunnan University of Chinese Medicine (Fig.S1). Disease incidence was about 11.0% during the field survey. Total RNA was extracted from symptomatic leaves of T. violacea plants using the TRIzol reagent (ambio, Carlsbad, CA). Reverse transcription (RT)-PCR was conducted to identify the virus using RNA extract as the template. The degenerate primers (dTospo-F2 and dTospo-R2) (Huang et al. 2018) were used to amplify the conserved regions of the orthotospoviral L RNA sequences. No amplification was obtained from extracts of two asymptomatic plants. The amplicons from four symptomatic samples were cloned into the pMD19-T vector (TaKaRa) and sequenced (three clones for each amplicon) by Tsingke (Shanghai, China). The obtained DNA fragments were determined to be 312 bp. The sequences from four symptomatic samples were identical (GenBank acc.no. OK258285) and shared the highest nucleotide identities (98.0%) with a corresponding sequence of segment L of impatiens necrotic spot virus (INSV) isolated (GQ336991) from Phalaenopsis amabilis in Yunnan province, China. To further confirm the INSV infection to T. violacea, the samples were analyzed with the specific primers for the N, NSs and NSm genes of INSV (Table S1), respectively. Amplicons of the expected size, 789 bp, 1344 bp and 912 bp, were produced, respectively. Amplicons were cloned and sequenced. The 789-bp N (ON529554) and 1344-bp NSs (ON529554) gene sequences had 99.1% and 99.3% nucleotide identities with the corresponding region of previously described INSV Phalenopsis isolate (GQ336989), respectively. The 912-bp NSm (ON529553) gene sequence shared 99.5% nucleotide identity with the corresponding region of INSV Phalenopsis isolate (GQ336990). Metavirome and Sanger sequencing were used to complete the genome of INSV from T. violacea. The leaves of the symptomatic sample were used to construct an rRNA-depleted library using Nextera XT reagents (Illumina, San Diego, CA). The library was subjected to RNA-Seq a NovaSeq 6000 platform (Illumina, San Diego, CA). A total of 33,193,233 quality-filtered reads were obtained using BBMAP (https://github.com/BioInfoTools/BBMapBBMap - Bushnell B. - sourceforge.net/projects/bbmap/). Among 161052 reads mapped to virus sequences, 151407 reads (read ratios 94.0%) were mapped to INSV. Three complete segments of INSV genome were determined to 8,778 nt (L segment, Acc. No. ON529552), 4,958 nt (M segment, Acc. No. ON529553), and 2,983 nt (S segment, Acc. No. ON529554) in length. These segments were validated by RT-PCR and Sanger sequencing. Three segments share nucleotide sequence identities of 99.6%, 99.3% and 98.9% with the L (GQ336991), M (GQ336990) and S segments (GQ336989) of INSV Phalenopsis isolate, respectively. The results of sequence comparisons showed no evidence of reassortment between INSV and another orthotospovirus. There was a report of tomato spotted wilt virus infecting T. violacea in Florida, USA (Dey et al. 2019). No other virus infecting T. violacea was reported. INSV has been reported to infect several economically important crops including Phalenopsis, pepper etc. in China (Chen et al. 2016). INSV-infected T. violacea not only losses landscaping value but also plays an important intermedia host role in the spread of INSV. Additional surveys and evaluation will be needed to understand the potential medicinal effect of this virus on this plant. To our knowledge, this is first report of INSV in T. violacea.

Clinical Features and Therapeutic Effects of Anti-leucine-rich Glioma Inactivated 1 Encephalitis: A Systematic Review.

Background: Clinical presentations and treatment programs about anti-leucine-rich glioma inactivated 1 (LGI1) encephalitis still remain incompletely understood. Objective: This study analyzed the clinical features and therapeutic effects of anti-LGI1 encephalitis. Methods: PubMed, EMBASE, and the Cochrane Library were searched to identify published English and Chinese articles until April 2021. Data were extracted, analyzed, and recorded in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. Results: A total of 80 publications detailing 485 subjects matched our inclusion criteria. Short-term memory loss (75.22%), faciobrachial dystonic seizures (FBDS) (52.53%), other seizures excluding FBDS (68.48%), psychiatric symptoms (57.67%), and sleep disturbances (34.30%) were the most frequently described symptoms in anti-LGI1 encephalitis. Hyponatremia (54.90%) was the most common hematologic examination change. The risk of incidence rate of malignant tumors was higher than in healthy people. The positive rate of anti-LGI1 in serum (99.79%) was higher than CSF (77.38%). Steroids (93.02%), IVIG (87.50%), and combined use (96.67%) all had a high remission rate in the initial visit. A total of 35 of 215 cases relapsed, of which 6/35 (17.14%) did not use first-line treatment, and 21 (60.00%) did not maintain long-term treatment. Plasma exchange (PE) could be combined in severe patients, immunosuppressant could be used for refractory patients or for recurrence and using an anti-epileptic drug to control seizures may benefit cognition. Conclusions: Short-term memory loss, FBDS, psychiatric symptoms, and hyponatremia were key features in identifying anti-LGI1 encephalitis. Serum and CSF antibody tests should be considered in diagnosis criteria. Steroids with IVIG should be recommended, PE was combined for use in severe patients, immunosuppressant therapy might improve outcomes if recurrence or progression occurred, and control seizures might benefit cognition. The useful ways to reduce relapse rate were early identification, clear diagnosis, rapid treatment, and maintaining long-term treatment. The follow-up advice was suggested according to the research of paraneoplastic syndrome, and concern about tumors was vital as well.

Experimental characterization of enhanced SNCR process with carbonaceous gas additives.

Carbonaceous gases such as CO and alkanes are commonly used as additives to enhance the selective non-catalytic reduction (SNCR) performance due to their high reducibility. This study compared the effect of CO and CH4 on NO reduction in a tubular reactor with simulated flue gas. The enhancement of C3H8 on SNCR process was tested at extremely low temperature, i.e. 650 °C. Experimental results suggested that reactions between NH3 and SO2 were favored at low temperatures and the competition for NH3 between SO2 and NO was influenced by gas additives. A maximum downward shift of 25 °C and 100 °C in temperature window for 50% NO reduction efficiency was obtained with the addition of CO and CH4, respectively. Considerable CO emission was observed with addition of CH4. The addition of CH4 contributed to the formation of a self-accelerating reaction route within NO/O2/NH3 SNCR reaction system. NO2 produced from NO accelerates the oxidation of CH4 to CO, while the oxidation of CH4 returns to enhance the NO reduction globally. Optimal NO reduction of 44% was achieved with addition of C3H8 at 650 °C. Substantial portion of C3H8 was partially oxidized to CO and the remaining was converted into C2H4 and C3H6 during the SNCR process. Oxidative dehydrogenation of C3H8 was involved. High reactivity of C3H6 and C2H4 favored the further oxidation and cracking to produce CO. These differences in oxidation behavior significantly influence the promotion capacities of CO, CH4 and C3H8 for NO reduction.

Innovative development path of ethnomedicines: the interpretation of the path.

One of the primary purposes of the innovative development of ethnomedicines is to use their excellent safety and significant efficacy to serve a broader population. To achieve this purpose, modern scientific and technological means should be referenced, and relevant national laws and regulations as well as technical guides should be strictly followed to develop standards and to perform systemic research in producing ethnomedicines. Finally, ethnomedicines, which are applied to a limited extent in ethnic areas, can be transformed into safe, effective, and quality-controllable medical products to relieve the pain of more patients. The innovative development path of ethnomedicines includes the following three primary stages: resource study, standardized development research, and industrialization of the achievements and efforts for internationalization. The implementation of this path is always guaranteed by the research and development platform and the talent team. This article is based on the accumulation of long-term practice and is combined with the relevant disciplines, laws and regulations, and technical guidance from the research and development of ethnomedicines. The intention is to perform an in-depth analysis and explanation of the major research thinking, methods, contents, and technical paths involved in all stages of the innovative development path of ethnomedicines to provide useful references for the development of proper ethnomedicine use.

[Research on Fenton treatment of the biochemical processes effluent of bamboo industry wastewater].

The decolorization and organic matter reduction of bamboo wastewater using Fenton oxidation was studied. Considering the cost and the removal efficiency, the optimal conditions were t = 30 degrees C, pH = 3.5, p(H2O2) = 1 665 mg x L(-1), c(Fe2+)/c(H2O2) = 0.072 and reaction time 3 h, with an initial COD and color concentration of wastewater of 430 mg x L(-1) and 1 500 times, under these conditions, the removal efficiency of COD and color could achieve 87.5% and 94.4%, respectively. It was found that the color reduction was higher than that of organics, and less affected by operation factors. The GC-MS analysis revealed that the chromophoric groups and auxochromic groups were greatly removed after Fenton treatment. The intermediates were mainly ester derivatives, and the by-products included 1-iodo-tridecane and 1,1'-oxybisoctane.

Ozonation as an advanced oxidant in treatment of bamboo industry wastewater.

The present study employed ozonation process to treat the bamboo industry wastewater (BIWW). The impact of ozone dosage and initial organic concentration on color, COD and TOC removal rates were studied along with characterization of the major organics in raw and treated wastewater. The results suggested the ozone dosage of 3.15 g h(-1) (concentration 52.5 mg L(-1)) was suitable for the treatment. After 25 min ozonation of 1L raw wastewater, the color, COD and TOC removal efficiencies were 95%, 56% and 40%, respectively, with an influent COD concentration of 835 mg L(-1). The ratio of kg O(3) kg(-1) COD at 3.15 g h(-1) was 2.8 (<3), revealing that ozonation was a cost effective process for tertiary treatment of BIWW. Longer oxidization time was required to achieve similar results for raw wastewater with higher COD concentration. The chromatogram from gel permeation chromatography revealed that ozonation resulted in the breakdown of high molecular weight compounds into lower molecular weight components but could not completely mineralize the organic matter. The majority of these compounds were identified in both raw and ozonated samples via GC-MS analysis. In addition to ester derivatives as the main intermediates of ozonation, 1-chloroctadecane, methyl stearate, benzophenone and α-cyperone were identified as the by-products of ozonation.

Inhibitory effects of Cu (II) on fermentative methane production using bamboo wastewater as substrate.

The toxic effects of Cu (II) present in bamboo industry wastewater (BIWW) upon its anaerobic biodegradability of organic content were investigated. The analysis through the Modified Gompertz model indicated that the optimum chemical oxygen demand (COD) concentration for digestion was 22,780 mg L(-1) with a maximum R(m) (maximum CH(4) production rate) value of 2.8 mL h(-1), corresponding to a specific methanogenic activity (SMA) of 2.38 mL CH(4) g VSS(-1)h(-1). The inhibitory effects of Cu (II) on cumulative methane production depended on its concentration and contact time. Low concentrations (5 mg L(-1)) of Cu (II) showed a stimulating effect on methanogenesis. Methane was not detected when the Cu (II) concentration was increased beyond 300 mg L(-1). The IC(50) value of Cu (II), the Cu (II) concentration that causes a 50% reduction in the cumulative methane production, was 18.32 mg L(-1) (15.9 mg Cu(II) gVSS(-1)).

[Effect of organs biomass by drought stress on the leaf growing stage of Angelica dahurica var. formosana].

OBJECTIVE: To study the effect of natural drought stress conditions on Angelica dahurica var. formnosana vegetative organs biomass accumulation and allocation in leaf growing season. To discuss the changing law of Angelica dahurica var. formosana vegetative organs biomass in different drought stress conditions. METHODS: Measured Angelica dahurica var. formnosana leaf and leafstalk's biomass, all aboveground biomass and the ratio of root biomass, leaf biomass, root/shoot ratio etc. in the growing season under the natural drought stress condition. RESULTS: Slight drought stress condition was good for organs' biomass accumulation, medium and serious drought stress conditions were bad for organs biomass accumulation. Slight and medium drought stress conditions were good for biomass transit to the root in the leaf growing season and serious drought stress condition was not good for that. CONCLUSION: Suitable drought stress can improve the root biomass ratio in Angelica dahurica var. formosana leaf growing season and get a better yield.

[Clinical trials of antiphlogistic agent series in treating chronic nonbacterial prostatitis].

OBJECTIVE: To investigate the curative effect of antiphlogistic agent series on treating chronic nonbacterial prostatitis (CNP). METHODS: One hundred and sixty patients were randomized into 4 groups for an 8-week clinical observation: group A (oral antiphlogistic medicinal granules only), group B (oral antiphlogistic medicinal granules + retention enema), group C (oral antiphlogistic medicinal granules + rectal), and group D (antiphlogistic medicinal granules + rectally + hip bath). Single blind trials were employed. RESULTS: The curative rates of the 4 groups were 37.5%, 57.5%, 52.5% and 82.5% respectively, while the total efficacy rates were 42.5%, 82.5%, 77.5% and 92.5% respectively. Compared with groups A, B and C, the curative rate of group D was significantly higher (P < 0.05). The difference in efficacy rates was slight between groups B and D (P < 0.05), but significant between groups A and C (P < 0.05). CONCLUSIONS: Combined treatment therapy can improve the effect of CNP treatment and clear away heat and toxic material. The antiphlogistic agent series, with the effect of motivating blood circulation and removing blood stasis, turned out to be an effective traditional Chinese medicine in treating CNP.