We have constructed a new bioreactor with reciprocal mixing that is better suited for the cultivation of delicate animal cells. In-silico simulation (computational fluid dynamics) suggested both maximum and average shear stresses in the bioreactor with reciprocal mixing to be remarkably lower than in conventional bioreactor with rotary mixing. Although we could not find any difference in growth speed and cell density between the bioreactors with reciprocal and rotary mixing, we did find cell viability in reciprocal-mixing bioreactor to be retained longer than in rotary-paddle bioreactor. This implied that cell culture in a bioreactor with reciprocal mixing could be prolonged for the production of target proteins. Leakage of lactate dehydrogenase activity into the culture medium was suppressed much more in the reciprocal-mixing bioreactor than in the rotary-paddle one. Production of human tissue plasminogen activator in the former was also observed to be much more than in the latter. Therefore, bioreactor with reciprocal mixing was concluded to be better suited for the cultivation of animal cells and efficient production of proteins, such as antibody drugs and various growth factors.
The regulation of cell density is an important segment in microfluidic cell culture, particularly in the repeated assays. Traditionally, the consistent cell density is difficult to achieve owing to the inaccurate regulation of cell density with manual feedback. A novel microfluidic culture method with automatic feedback is proposed for real-time regulation of cell density in this paper. Here, an integrated microfluidic system combining cell culture, density detection and control of proliferation rate was developed. Interdigital electrode structures (IDES) are sputtered on the microchannel for automatically providing the real-time feedback information of impedance. The most sensitive frequency is studied to improve the detection resolution of the sensing chip. Cells were cultured on the chip surface and the cell density was detected by monitoring the alternation of the impedance. The feedback controller is established by least squares support vector machines (LS-SVM). Then, the cell proliferation rate was automatically controlled using the feedback controller to achieve the desired cell density in the repeated assays. The results show that the standard error of this method is 2.8% indicating that the method can keep consistency of cell density in the repeated assays. This study provides a basis for improving the accuracy and repeatability in the further assays of finding the optimal drug concentration.
Patients in sub-Saharan Africa generally have poor anticoagulation control. We review the potential reasons for this poor control, as well as the potential solutions. Challenges include the affordability and centralisation of anticoagulation care, problems with access to medicines and INR monitoring, the lack of locally-validated standardized dosing protocols, and low levels of anticoagulation knowledge among health care workers and patients. Increasing numbers of patients will need anticoagulation in the future because of the epidemiological transition in the region. We propose that locally-developed “warfarin care bundles” which address multiple anticoagulation challenges in combination may be the most appropriate solution in this setting currently.
Single cell analysis has numerous potential applications, for instance in the context of myotonic dystrophy type I (DM1). This disease is caused by a CTG expansion in the dystrophia myotonica-protein kinase (DMPK) gene, with CTG expansion length being heterogeneous not only between tissues but also between cells in the same tissue. We studied muscle pathophysiology from five patients with DM1 at single cell level, including RNA foci (i.e., nuclear DMPK-transcribed aggregates that trap proteins) and splicing alterations (caused by trapping of important splicing regulator proteins by the RNA foci). Single cell myoblasts were heterogeneous in RNA foci load, with most showing 0 to 3 foci. The percentage of myoblasts carrying foci differed among patients, ranging from 29 to 99%. We found a significant direct correlation between mean and median number of RNA foci in myoblasts and patients’ endurance capacity (r=-0.975, p=0.005). Although the expression of DMPK and MBNL1 transcripts was variable among the myoblasts, no relationship was found between RNA foci number and their expression in individual cells. CTG size in muscle correlated with patients´ disease onset. In summary, single cell analysis poses some technical challenges but allows an in-depth analysis of heterogeneous molecular alterations in patients with DM1.
The prenatal diagnosis of fetal anomalies started with the development of X-ray. In 1943, Hartley and Burnet, Radiologists in Manchester (J Obstet Gynaecol Brit Empire,1943;50:1-12), reported a series of 11 cases of “croaniolacunia” or lacunar skull, a condition often associated at births with spina bifida or encephalocele. These cases were all diagnosed in the third trimester of pregnancy and the radiograph features believed to be due to the effect of increased intracranial pressure on the fetal skull of hydrocephaly. Until the end of the 1960s, radiography remained the main technique to diagnose congenital abnormalities. In 1969, Russell (J Obstet Gynaecol Br Commonw,1969;76:345-50), also a consultant radiologist from Manchester, compared the accuracy of antenatal radiology examinations with paediatric reports in the diagnosis of anencephaly and other major neural tube defects, skeletal abnormalities such as achondroplasia and severe exomphalos when associated with rib deformities. Overall, the accuracy of the radiological diagnosis was considered as “strikingly” accurate for neural tube defects with 88 out of 113 cases of anencephaly diagnosed before delivery. Although, the author did not provide the gestational age at diagnosis, the images included in the article indicate that these were obtained in the third trimester. As neonatal care and surgery were in their infancy at the time, the main objective in diagnosing these anomalies was not the fetus but the need to identify antenatally mothers at risk of obstructed labour.Not surprisingly, some of the first publications by the team of Ian Donald in Glasgow were on the antenatal use of ultrasound imaging in the evaluation of the size of the fetal head (Willocks et al., J Obstet Gynaecol Br Commonw,1964;71:11-20). The fetal head was the only structure that could be measured and biparietal diameter the only measurement that could be obtained with the “ultrasound beam” of the first ultrasound machine (Figure). The technique called “cephalometry” was used at the end of the third trimester to assess “growth and maturity” of the fetus and “disproportion” and was found to be more reliable with ultrasound than X-ray. It would be another decade, before ultrasound imaging could reliably identify fetal anomalies such as spina-bifida in the second trimester of pregnancy (Campbell et al., Lancet,1975;1(7920):1336-7). However, the use of ultrasound imaging in the mid-seventies to search for major neural tube defects was always triggered by high levels of maternal serum alpha-fetoprotein. As there were few ultrasound equipment available and few trained operators, this biomarker was to remain for two decades the first line of action in the antenatal screening strategy for spina-bifida. The advent of high-resolution imaging, access low-cost and mobile ultrasound equipment and the training of more specialists and sonographers has moved the antenatal screening and diagnosis of many fetal anomalies to 11-14 weeks of gestation (Ushakov et al., UOG,2019;54:740-5).The systematic review by Drukker et al. (BJOG 2020) brings the focus back to late pregnancy: even in our exciting modern era of early anomaly scanning, a fetal abnormality will still be found in about 1 in 300 women scanned in the third trimester.Word count: 500BJOG since 1902 Perspectives on BJOG-20-0525R1
Algae are promising feedstock of biofuel. The screening of competent species and proper fertilizer supply are of the most important tasks. To accelerate this rather slow and laborious step, we developed an integrated high-throughput digital microfluidic (DMF) system that uses discrete droplet to serve as micro-bioreactor, encapsulating microalgal cells. Based on the fundamental understanding of various droplet hydrodynamics induced by the existence of different sorts of ions and biological species, an incorporation of capacitance-based position estimator, electrode-saving-based compensation and deterministic splitting approach was performed to optimize the DMF bioreactor. Thus, it enables all processes (e.g. nutrient gradient generation, algae culturing and analyzing of growth and lipid accumulation) occurring automatically on-chip especially in a high-fidelity way. The ability of the system to compare different micro algal strains on chip was investigated. Also, the Chlorella sp. were stressed by various conditions and then growth and oil accumulation were analyzed and compared, which demonstrated its potential as a powerful tool to investigate microalgal lipid accumulation at significantly lower laborites and reduced time.
Traditional cell line development is based on random genomic integration of transgenes. Random integration leads to unpredictable expression and results in clonal heterogeneity requiring a tedious screening procedure. Therefore, a new strategy is needed to establish clones that exhibit stable transgene expression. Here, we performed CRISPR/Cas9-mediated site-specific integration (SSI) to incorporate a landing pad (LP; containing mCherry) at a genomic hotspot (Fer1L4) allowing stable and strong expression. Site-specific integration of LP on Fer1L4 was demonstrated by sequencing results representing the swapped sequences in mCherry-expressing cells. We then performed Cre/Lox-based recombinase-mediated cassette exchange (RMCE) to exchange LP with a targeting vector (TV; containing GFP) in clones established by CRISPR/Cas9-mediated SSI. The success of Cre/Lox-based RMCE was evidenced by sequencing results representing the swapped sequences in GFP-expressing cells. Furthermore, the swapped clones expressing GFP was enriched up to 80%, indicating that the efficiency of Cre/Lox-based RMCE would be sufficient to swap pre-existing cassettes with gene-of-interest (GOI). Taken together, our study provides a new platform for Cre/Lox-based RMCE to iteratively establish stable clones from existing ones previously established by SSI at a genomic hotspot.
Cor-triatriatum sinister (CTS) is a rare congenital condition in which the left atrium is divided into two chambers. Patients can present as infants or later in life, which is largely dependent on the size of fenestration between these two chambers. Surgical excision of the membrane is curative. This is traditionally performed through a median sternotomy. Here we report of a case of a 60-year old man who presented to his primary care physician with dyspnea and atrial fibrillation. He was found to have CTS. We performed excision of the left atrial membrane and maze procedure through a left anterolateral mini-thoracotomy with femoral cannulation.
Extracorporeal life support (ECLS) is an expanding technology for patients in cardiogenic shock. Most patients requiring ECLS can be managed with percutaneous veno-arterial (VA) femoral cannulation. Despite sufficient extracorporeal circulatory support, an unclear number of patients develop left ventricular distension which can result in increased wall tension and stress as well as worsening pulmonary edema. Indications to vent the left ventricle can be controversial. When venting is indicated a number of additional procedures may be considered including inotropic support, intra-aortic balloon pump, Impella, balloon atrial septostomy, or placement of a transseptal cannula. We present a unique case of a femoral VA Extracorporeal membrane oxygenation (ECMO) as bridge to transplant (BTT) with left-sided venting using a Bio-medicus NextGen cannula (Medtronic) with a transseptal approach.
Nonspecific Lipid Transfer Proteins (nsLTP2) are small and soluble proteins, which due to their unique features have the ability of binding to lipids and some pharmaceutical compounds, are considered as good options for drug delivery systems. Their stability against proteolysis and thermal denaturation leads to allergenic reactions which limit its clinical usage. The bioinformatics approach was carried out to hydrophobicity and antigenicity analysis of Oryza sativa (Iranian group) nsLTP2. Using Molegro Virtual Docker software, the affinity and binding strength of several fatty acids, steroid-based anti-viral, and anti-tumor drugs with nsLTP2 were identified. Results demonstrated that there is only one transmembrane segment in the nsLTP2 protein sequence which is located in the signal peptide region, also calculating the average antigenicity propensity (AP) of amino acids showed that concurrent mutations of C26N/N53F can reduce the antigenic propensity of these proteins. Furthermore, Abacavir (MolDock Score = -119.348), DHA (MolDock Score = -152.601), and Basedoxifene (MolDock Score = -156.776) could be considered as the best antiviral, phospholipid, and anticancer ligands for it, respectively.
In the present study, the microstructure evolution and material properties variation mechanism of austenitic stainless steel under pre-strain were discussed. A bilinear relationship between material properties and pre-strain was established. Both yield strength and tensile strength of the austenitic stainless increase with the increase of pre-strain, but the increment of yield strength is obviously greater than that of the tensile strength. A critical pre-strain point was put forward. When the pre-strain is lower than critical value, there is only work hardening. And when it is higher than critical value, the material properties are affected by the combined effects of work hardening and martensitic transformation. The effect of critical pre-strain is also found in the study of fatigue limit. The inherent essence of fatigue limit improvement of pre-strained material lies in the comprehensive effect of material phase transformation and plastic deformation strengthening.
Infiltration and soil water content (SWC) are key concerns to agro-hydrological researchers. Understanding of irrigation-induced infiltration and soil water characteristics are fundamental to irrigation management and improving agricultural Water Use Efficiency (WUE) in arid and semi-arid areas. Based on measurements from a test site in Xinjiang, China, numerical simulations have been performed to investigate the infiltration processes under alternating drip irrigation operations. The present study focuses on simulating infiltration physics and analyzing its potential impacting factors, to shed light on the design of irrigation systems that improve WUE. The results show that irrigation schedules, surface sealing, residual water saturation, and soil fractures have significant impacts on SWC patterns for both the irrigation durations and intermittences. Low frequency irrigation with high watering rates should be avoided due to its low irrigation efficiency. Commencing with lower-rate irrigation is probably the best practice for efficient irrigation for shallow-root crops. The soil infiltrability drops exponentially or polynomially with the decrease in permeability of the immediate surface. Introduction of a 5-mm soil surface seal with a permeability of 5 mD leads to about 97.1% reduction in the infiltrability. Residual water saturation Swr or water content has positive correlations with Volumetric soil Water Content (VWC), due to the trapping of the residual water. Enhancement of one-fold magnitude of Swr causes 6.12% and 20.4% higher VWC for the loamy sand, but 7.57% and 5.71% lower VWC for the underlying sandy loam, at the 160 hr and 720 hr respectively. The presence of soil fractures leads to apparent preferential flows in the soil, which cause the wet fronts to penetrate to 115.9% and 53.88% deeper depths at the 160 hr and 720 hr, respectively.
Hyperexcitability-related diseases include epilepsies, pain syndromes, neuromuscular disorders, and cardiac arrhythmias. Sodium channel inhibitors can be used to treat these conditions, however, their applicability is limited by their nonspecific effect on physiological function. They act by channel block (obstructing ion conduction, since the binding site is within the channel pore), and by modulation (delaying recovery from the non-conducting inactivated state). Channel block inhibits healthy and pathological tissue equally, while modulation can preferentially inhibit pathological activity. Therefore, an ideal sodium channel inhibitor drug would act by modulation alone. Unfortunately, thus far no such drug has been known to exist. Here we present evidence that riluzole acts by this “ideal” mechanism, “non-blocking modulation” (NBM). We propose that, being a relatively small molecule, riluzole is able to stay bound to the binding site, but nonetheless stay off the conduction pathway, by residing in one of the “fenestrations” (cavities connecting the central cavity to the membrane phase). Using precisely timed UV pulses to photolabel specific conformations of the channel, we show that association to the local anesthetic binding site requires prior inactivation. We discuss why kinetics of binding is crucial for selective inhibition of pathological activity, and how the NBM mechanism can be recognized using a special voltage- and drug application-protocol. Our results identify riluzole as the prototype of this new class of sodium channel inhibitors. Drugs of this class are expected to selectively prevent hyperexcitability, while having minimal effect on cells firing at a normal rate from a normal resting potential.
Microorganisms play a key role in aquatic ecosystems. Recent studies have showed that some keystone taxa in microbial communities can drive the changes in community composition and function. However, most studies have focused on abundant taxa, whereas rare taxa are neglected because of their low abundance. Therefore, it is important to clarify the seasonal variation of bacterial and microalgal communities and understand the synergistic adaptation of these organisms to different environmental factors. We investigated the bacterial and eukaryotic phytoplankton communities and their seasonal co-occurrence patterns using16S and 18S rDNA sequencing approach. Our results indicated that in eukaryotic phytoplankton networks, spring and autumn networks had higher connectivity and complexity, forming the highly stable community structure. The positive interactions of bacterial network were significantly higher than the negative interactions, indicating that more mutual cooperation can make the microbial communities better resist changes in the external environment, thereby maintaining the stability of microbial network. The main genera identified as keystone taxa in bacterial networks were Pseudomonas, Stenotrophobacter, Bosea, and Hyphomicrobium, which were significantly related to many predicted functions. The main genera identified as keystone taxa in eukaryotic phytoplankton networks were Monodus, Tetradesmus, Scenedesmus, Monoraphidium, and Amphora, which were affected by dissolved organic carbon, nitrate, nitrite, and phosphate, changes in these environmental factors can affect the stability of network. Through the co-occurrence patterns, we analyzed the internal mechanism of interaction between bacteria and eukaryotic phytoplankton and understood the potential importance of keystone taxa in ecological processes such as carbon, nitrogen, and phosphorus dynamics.
Non-consumptive predator effects (NCEs) are now widely recognized for their capacity to shape ecosystem structure and function. Yet, forecasting the propagation of these predator-induced trait changes through particular communities remains a challenge, in part because we lack a predictive framework that accounts for environmental and species context. Accordingly, focusing on plasticity in prey anti-predator behaviors, we conceptualize the multi-stage process by which predators trigger direct and indirect NCEs, review and then distill potential drivers of NCE contingencies into three key categories (properties of the prey, predator, and setting), and conduct a meta-analysis to quantify the extent to which prey behavioral plasticity in response to predation risk hinges on a well-studied driver – prey energetic state. Our synthesis underscores the myriad factors that can generate NCE contingencies while guiding how research might better anticipate and account for them. We highlight two key knowledge gaps that continue to hinder development of a comprehensive framework for exploring non-consumptive predator-prey interactions. These are insufficient exploration of 1) context-dependent indirect NCEs and 2) the ways in which direct and indirect NCEs are shaped interactively by multiple drivers of context dependence.
As global change forces species’ ranges and abundances into novel configurations, traits-based approaches could allow predictions of community re-assembly. We present a quantitative review of traits-based research globally to (1) evaluate the extent to which this approach has been applied, and (2) evaluate moving from description and to prediction. We highlight the application of traits-based frameworks to describe ecological patterns; terrestrial plant morphology comprises >30% of the literature alone. But fewer than 3% of studies predict ecological effects of global change, mostly in the past five years. While organism size is the most common trait, we identified 2,430 other morphological, physiological, behavioural, and life history traits that mediate environmental filters of species’ ranges across ecosystems and taxonomy. Global change studies forecast range shifts from a few physiological or life history traits. Though uncommon, spatially-explicit models constructed from correlated multivariate trait assemblages (or ‘syndromes’) offer the best chance of predicting shifts under global change scenarios. Moving the field towards trait-based prediction requires (1) matching the scale of trait measurement to the ecological processes, (2) increasing the resolution of environmental gradients along which traits are measured, (3) moving from single to multivariate traits, and (4) accounting for intraspecific trait variation.
Abstract Introduction The excellent coordination and action by the Ministry of Health of the Nation with the 24 provinces and between the Autonomous City of Buenos Aires and the metropolitan area of the homonymous Province, resulted in the moment, in mortality less than 2% and occupation of critical care beds that does not exceed 63%,.Material and Methods Regarding cardiovascular care in the group of patients over 65 years of age, a more accurate analysis could be performed when two comparative half-yearly periods corresponding to the years 2019 and 2020 (pandemic time) were compared. The data collected regarding this age range revealed issues that had not previously been evaluated in our country. That undoubtedly proposes a different solution for the future based on a strict scientific analysis Results, for example, the number of patients who received a stent in relation to coronary artery surgery is greater than 6 to 1, and compared to surgery without pump and minimally invasive from 69 to 1 Conclusion The Argentinian Perspective is good because has an excellent level of qualified medical training in its cardiac and interventional Cardiologist services, as well as healthcare infrastructure distributed throughout the country, which will undoubtedly be able to respond to the new challenges posed for the post-pandemic stage
Objective: Vitamin D deficiency is claimed to be associated with many diseases in the world populations. Many studies reported that vitamin D deficiency is quite prevalent in Pakistan. The aim of this review is to describe the current status of vitamin D deficiency in healthy individuals and in different disease conditions in this country. Methods: Search engines such as “Google Scholar”, “Medline and PubMed” were used by applying key words such as vitamin D deficiency, vitamin D deficiency and different disease conditions in Pakistani population. Results: Total 82 studies were included in which 12 studies showed vitamin levels less than 30 ng/mL in the healthy individuals (male and female) and 70 studies in different disease conditions. It found that about 64.6% healthy subjects had vitamin D levels less than 30 ng/mL. Moreover, 70 studies showed its deficiency in some diseases such as musculoskeletal, bone and periodontal problems, nursing mothers and children, tuberculosis, diabetes, cardiovascular problems and some type of cancers. Conclusion: The current status of vitamin D deficiency in healthy population and in several diseases and conditions are thoroughly discussed in this review. This review could be helpful to understand status of vitamin D and different aspects of vitamin D research in this population