Response and acclimation of cyanobacteria to acidification: A comprehensive review.

Cyanobacteria, as vital components of aquatic ecosystems, face increasing challenges due to acidification driven by various anthropogenic and natural factors. Understanding how cyanobacteria adapt and respond to acidification is crucial for predicting their ecological dynamics and potential impacts on ecosystem health. This comprehensive review synthesizes current knowledge on the acclimation mechanisms and responses of cyanobacteria to acidification stress. Detailly, ecological roles of cyanobacteria were firstly briefly concluded, followed by the effects of acidification on aquatic ecosystems and cyanobacteria. Then the review focuses on the physiological, biochemical, and molecular strategies employed by cyanobacteria to cope with acidification stress, highlighting key adaptive mechanisms and their ecological implications. Finally, a summary of strategies to enhance acid resistance in cyanobacteria and future directions was discussed. Utilizing omics data and machine learning technology to build a cyanobacterial acid regulatory network allows for predicting the impact of acidification on cyanobacteria and inferring its broader effects on ecosystems. Additionally, acquiring acid-tolerant chassis cells of cyanobacteria through innovative techniques facilitates the advancement of environmentally friendly production of acidic chemicals. By synthesizing empirical evidence and theoretical frameworks, this review aims to elucidate the complex interplay between cyanobacteria and acidification stressors, providing insights for future research directions and ecosystem management strategies.

Engineered Cyanobacteria-Based Living Materials for Bioremediation of Heavy Metals Both In Vitro and In Vivo.

The pollution caused by heavy metals (HMs) represents a global concern due to their serious environmental threat. Photosynthetic cyanobacteria have a natural niche and the ability to remediate HMs such as cadmium. However, their practical application is hindered by a low tolerance to HMs and issues related to recycling. In response to these challenges, this study focuses on the development and evaluation of engineered cyanobacteria-based living materials for HMs bioremediation. Genes encoding phytochelatins (PCSs) and metallothioneins (MTs) were introduced into the model cyanobacterium Synechocystis sp. PCC 6803, creating PM/6803. The strain exhibited improved tolerance to multiple HMs and effectively removed a combination of Cd2+, Zn2+, and Cu2+. Using Cd2+ as a representative, PM/6803 achieved a bioremediation rate of approximately 21 µg of Cd2+/OD750 under the given test conditions. To facilitate its controllable application, PM/6803 was encapsulated using sodium alginate-based hydrogels (PM/6803@SA) to create "living materials" with different shapes. This system was feasible, biocompatible, and effective for removing Cd2+ under simulated conditions of zebrafish and mice models. Briefly, in vitro application of PM/6803@SA efficiently rescued zebrafish from polluted water containing Cd2+, while in vivo use of PM/6803@SA significantly decreased the Cd2+ content in mice bodies and restored their active behavior. The study offers feasible strategies for HMs bioremediation using the interesting biomaterials of engineered cyanobacteria both in vitro and in vivo.

Gut microbiota and cardiac arrhythmia.

One of the most prevalent cardiac diseases is cardiac arrhythmia, however the underlying causes are not entirely understood. There is a lot of proof that gut microbiota (GM) and its metabolites have a significant impact on cardiovascular health. In recent decades, intricate impacts of GM on cardiac arrythmia have been identified as prospective approaches for its prevention, development, treatment, and prognosis. In this review, we discuss about how GM and its metabolites might impact cardiac arrhythmia through a variety of mechanisms. We proposed to explore the relationship between the metabolites produced by GM dysbiosis including short-chain fatty acids(SCFA), Indoxyl sulfate(IS), trimethylamine N-oxide(TMAO), lipopolysaccharides(LPS), phenylacetylglutamine(PAGln), bile acids(BA), and the currently recognized mechanisms of cardiac arrhythmias including structural remodeling, electrophysiological remodeling, abnormal nervous system regulation and other disease associated with cardiac arrythmia, detailing the processes involving immune regulation, inflammation, and different types of programmed cell death etc., which presents a key aspect of the microbial-host cross-talk. In addition, how GM and its metabolites differ and change in atrial arrhythmias and ventricular arrhythmias populations compared with healthy people are also summarized. Then we introduced potential therapeutic strategies including probiotics and prebiotics, fecal microbiota transplantation (FMT) and immunomodulator etc. In conclusion, the GM has a significant impact on cardiac arrhythmia through a variety of mechanisms, offering a wide range of possible treatment options. The discovery of therapeutic interventions that reduce the risk of cardiac arrhythmia by altering GM and metabolites is a real challenge that lies ahead.

Clinical Efficacy of Blood Ultrafiltration Therapy in Patients with Acute Decompensated Chronic Heart Failure Running Title: Blood Ultrafiltration Therapy for Heart Failure.

In this study, we investigated the clinical effects of blood ultrafiltration therapy in patients with acute decompensated chronic heart failure. We enrolled 78 patients with acute decompensated chronic heart failure who were admitted to a hospital from September 2017 to December 2021, and divided them into two groups based on the digital randomization method. The FQ-16 heart failure ultrafiltration dehydrating device blood ultrafiltration therapy was administered to the observation group (39 patients) for 8-16 hours, while the control group (39 patients) received the stepped drug therapy. Echocardiography was used to assess the changes in cardiac function of the patients in both groups before and after treatment. The changes in urine volume, N-terminal pro-B-type natriuretic peptide (NT-proBNP), plasma renin, and serum creatinine levels were measured before and after the treatment to compare the overall response rate of the patients in both groups. The differences in left ventricular end-systolic dimension and left ventricular end-diastolic dimension and the ejection fraction between the groups before treatment were not statistically significant (P > 0.05), however, the left ventricular end-diastolic dimension in the observation group was significantly lower and the ejection fraction was significantly higher (P < 0.05) compared with that before treatment; the urine volume, N-terminal pro-B-type natriuretic peptide (NT-proBNP), plasma renin, and serum creatinine were significantly improved in both groups after treatment compared with that before treatment. All indexes in the observation group were better than those in the control group (P < 0.05), 74.36%. The overall response rate of the observation group was 94.87%, x2 = 4.843 and the difference between groups was statistically significant (P < 0.05). Blood ultrafiltration therapy for patients with acute decompensated chronic heart failure can improve their cardiac and renal functions, reduce NT-proBNP, reduce volume load, and enhance efficacy while ensuring high safety.

[Application of synthetic small regulatory RNAs in synthetic biology].

Synthetic biology has brought enormous impacts to the advancement of agriculture, energy, manufacturing and medicine by redesigning existing natural systems or creating biological elements, modules and systems to endow life with new functions. The precise, quantitative and efficient regulation of biological elements, modules and systems is critical for controlling living systems. Bacterial small regulatory RNAs are a class of functional molecules with a length of 50-300 nt and usually do not translate into proteins. They play an irreplaceable role in environmental stress response, metabolic adaptation and bacterial virulence control. In recent years, synthetic small regulatory RNAs have been designed based on natural small RNAs and were used to effectively inhibit or activate target genes and even pathways. Synthetic small regulatory RNAs have broad application advantages in synthetic biology because of their small size, high flexibility, programmability, easy design and little metabolic burden on host cells. To better understand the synthetic small regulatory RNAs and promote its application, this review summarized several synthetic small RNA systems and their representative applications in synthetic biology. Finally, future optimization directions were prospected.

Development of a N-Acetylneuraminic Acid-Based Sensing and Responding Switch for Orthogonal Gene Regulation in Cyanobacterial Synechococcus Strains.

Advances in synthetic biology have allowed photosynthetic cyanobacteria as promising "green cell factories" for sustainable production of biofuels and biochemicals. However, a limited of genetic switches developed in cyanobacteria restrict the complex and orthogonal metabolic regulation. In addition, suitable and controllable switches sensing and responding to specific inducers would allow for the separation of cellular growth and expression of exogenous genes or pathways that cause metabolic burden or toxicity. Here in this study, we developed a genetic switch repressed by NanR and induced by N-acetylneuraminic acid (Neu5Ac) in a fast-growing cyanobacterium Synechococcus elongatus UTEX 2973 along with its highly homologous strain S. elongatus PCC 7942. First, nanR from Escherichia coli and a previously optimized cognate promoter PJ23119H10 were introduced into Syn2973 to control the expression of the reporter gene lacZ encoding ß-galactosidase, achieving induction with negligible leakage. Second, the switch was systemically optimized to reach ∼738-fold induction by fine-tuning the expression level of NanR and introducing additional transporter of Neu5Ac. Finally, the orthogonality between the NanR/Neu5Ac switch and theophylline-responsive riboregulator was investigated, achieving a coordinated regulation or binary regulation toward the target gene. Our work here provided a new switch for transcriptional control and orthogonal regulation strategies in cyanobacteria, which would promote the metabolic regulation for the cyanobacterial chassis in the future.

Pregnancy complications among nulliparous and multiparous women with advanced maternal age: a community-based prospective cohort study in China.

BACKGROUND: This study aimed to evaluate the incidence rates and risks of pregnancy complications among nulliparous and multiparous women with advanced maternal age (AMA, ≥35 years) in China. METHODS: We performed a community-based prospective cohort study of 10,171 pregnant women in selected two sub-districts and 11 towns of Liuyang from 2013 to 2015. All subjects were followed up from the first prenatal care (at ≤12 weeks) to delivery, and risks of pregnancy complications were compared by parity and maternal age groups. RESULTS: Among nulliparas, women with AMA showed significantly increased risks for gestational hypertension (OR 8.44, 95%CI 1.68-2.88), preeclampsia/eclampsia (OR 9.92, 95%CI 4.87-18.78), premature rupture of membrane (OR 6.84, 95%CI 2.00-17.69), as compared to women in the 20-29-year age group. Among multiparas with AMA, increased risks were found for gestational diabetes mellitus (OR 3.29, 95%CI 1.76-5.94), anemia (OR 1.85, 95%CI 1.25-2.69), polyhydramnios (OR 3.29, 95%CI 1.56-6.64), premature rupture of membrane (OR 5.14, 95%CI 2.12-12.29), and preterm labor (OR 1.89, 95CI 1.42-2.50). CONCLUSIONS: Women with AMA were associated with increased risks of pregnancy complications, and complications with increased risks differed in nulliparas and multiparas. Women with AMA should be identified as a high-risk group in clinical practice.

Effect of Huayu Tongluo Herbs on Reduction of Proteinuria via Inhibition of Wnt/ß-Catenin Signaling Pathway in Diabetic Rats.

The study investigated the expression of Wnt/ß-catenin pathway in diabetic rats and the intervention effect of Huayu Tongluo herbs (HTH). Ten rats were randomly selected as control group and the remaining rats were established as diabetic models. The diabetic rats were randomly divided into model group and HTH treatment group. The intervention was intragastric administration in all rats for 20 weeks. At the end of every 4 weeks, fasting blood glucose and 24 h urinary total protein quantitatively were measured. At the end of the 20th week, biochemical parameters and body weight were tested. The kidney tissues were observed under light microscope and transmission electron microscopy. We examined Wnt/beta-catenin signaling pathway key proteins and renal interstitial fibrosis related molecular markers expression. The results showed that HTH could reduce urinary protein excretion and relieve renal pathological damage. Wnt4, p-GSK3ß (S9), and ß-catenin expression were decreased in the signaling pathway, but GSK3ß level was not changed by HTH in diabetic rats. Furthermore, the expressions of TGF-ß1 and ILK were decreased, but the level of E-cadherin was increased in diabetic rats after treatment with HTH. This study demonstrated that HTH could inhibit the high expression of Wnt/ß-catenin pathway in kidney of diabetic rats. The effect might be one of the main ways to reduce urinary protein excretion.

Cascade control of superheated steam temperature with neuro-PID controller.

In this paper, an improved cascade control methodology for superheated processes is developed, in which the primary PID controller is implemented by neural networks trained by minimizing error entropy criterion. The entropy of the tracking error can be estimated recursively by utilizing receding horizon window technique. The measurable disturbances in superheated processes are input to the neuro-PID controller besides the sequences of tracking error in outer loop control system, hence, feedback control is combined with feedforward control in the proposed neuro-PID controller. The convergent condition of the neural networks is analyzed. The implementation procedures of the proposed cascade control approach are summarized. Compared with the neuro-PID controller using minimizing squared error criterion, the proposed neuro-PID controller using minimizing error entropy criterion may decrease fluctuations of the superheated steam temperature. A simulation example shows the advantages of the proposed method.

[Protective effects of Chailing Guiqi Decoction combined with lumbrukinase on renal function in rats with adriamycin nephropathy].

OBJECTIVE: To study the protective efffects of Chailing Guiqi Decoction (CLGQD) combined with lumbrukinase on renal function in rats with adriamycin nephropathy. METHODS: Thirty-six SD rats were randomly divided into four groups: normal control group, untreated group, simvastatin-treated group and CLGQD -treated group. Adriamycin nephropathy was induced by intravenous injection with 5 mg/kg adriamycin. After seven-day treatment, quantitative measurement of 24-h urine protein was determined with trichloroacetic acid, and serum total protein (TP), albumin (Alb), total cholesterol (TC), triglycerides (TG), high-density lipoprotein (HDL), low-density lipoprotein (LDL), creatinine (Cr) and blood urea nitrogen (BUN) were assessed using automatic biochemistry analyzer. The pathomorphological changes of renal tissues were observed with light and electron microscopes. RESULTS: In the untreated group, the 24-h urine protein excretion, serum TC, TG, LDL, Cr and BUN were significantly higher than those in the normal control group (P<0.05 or P<0.01), while the serum TP, Alb, HDL were significantly lower than those in the normal control group (P<0.01). In the CLGQD-treated group, the 24-h urine protein excretion, serum TC, TG, LDL, Cr and BUN were significantly lower as compared with those in the untreated group (P<0.05 or P<0.01), while the serum TP, Alb and HDL were significantly higher as compared with those in the untreated group (P<0.05 or P<0.01). The pathomorphological findings of the renal tissues under the light microscope in the untreated group showed focal segmental glomerulosclerosis in a few of glomerulus, degenerated and swelled proximal tubular epithelial cells, proteins in cast formation in some renal tubules and scattered fibrosis in interstitial tissues of the kidney, while the electron microscope images showed the fusion of foot processes in glomerular epithelial cells. The pathomorphological changes in the CLGQD-treated group were slighter than those in the untreated group. CONCLUSION: CLGQD combined with lumbrukinase can reduce proteinuria, regulate lipid metabolism, protect renal function, and delay progressive renal damage in rats.