Exogenous melatonin alleviates PEG-induced short-term water deficiency in maize by increasing hydraulic conductance.

BACKGROUND: Water deficiency is likely to become more frequent and intense as a result of global climate change, which may severely impact agricultural production in the world. The positive effects of melatonin (MEL) on alleviation drought or osmotic stress-induced water deficiency in plants has been well reported. However, the underlying mechanism of MEL on the detailed process of plant water uptake and transport under water deficiency condition remains largely unknown. RESULTS: Application of 1 µM MEL led to enhanced tolerance to water deficiency stress in maize seedlings, as evidenced by maintaining the higher photosynthetic parameters, leaf water status and plant transpiration rate. The relatively higher whole-plant hydraulic conductance (Kplant) and root hydraulic conductance (Lpr) in MEL-treated seedlings suggest that exogenous MEL alleviated water deficiency stress by promoting root water absorption. HgCl2 (aquaporin inhibitor) treatment inhibit the transpiration rate in MEL-treated plants greater than those of MEL-untreated; after recovery by dithiothreitol (DTT, anti-inhibitor), the transpiration rate in MEL-treated plants increased much higher than those of untreated plants. Moreover, under water deficiency, the transcription level of aquaporin genes was up-regulated by MEL application, and the H2O2 was less accumulated in MEL-treated root. CONCLUSIONS: Exogenous MEL promoted aquaporin activity, which contributed to the maintaining of Lpr and Kplant under short-term water deficiency. The increased water uptake and transport lead to improved water status and thus increased tolerance to PEG-induced short-term water deficiency in maize seedlings.

Nanocrystalline Cellulose-Assisted Generation of Silver Nanoparticles for Nonenzymatic Glucose Detection and Antibacterial Agent.

Nanocrystalline cellulose (NCC) is a kind of natural biopolymers with merits of large surface area, high specific strength and unique optical properties. This report shows that NCC can serve as the substrate, allowing glucose to reduce Tollen's reagent to produce silver nanoparticles (AgNPs) at room temperature. The generation of AgNPs is affected by the factors such as the concentrations of silver ions, NCC and glucose, as well as the different reaction temperatures. The AgNPs with NCC are applied for the development of a visual, quantitative, nonenzymatic and high-sensitive assay for glucose detection in serum. This assay is also used for monitoring the concentration change of glucose in medium during cell culture. For the antibacterial activity, the minimal inhibitory concentration (MIC) of the generated AgNPs with NCC is much lower than that of commercial AgNPs, attributed to the good dispersion of AgNPs with the presence of NCC. As NCC exhibits unique advantages including green, stable, inexpensive, and abundant, the NCC-based generation of AgNPs may find promising applications in clinical diagnosis, environmental monitoring, and the control of bacteria.

Evaluation of the effect of the structure of bacterial cellulose on full thickness skin wound repair on a microfluidic chip.

Bacterial cellulose (BC) is a kind of nanobiomaterial for tissue engineering. How the nanoscale structure of BC affects skin wound repair is unexplored. Here, the hierarchical structure of BC films and their different effects on skin wound healing were studied both in vitro and in vivo. The bottom side of the BC film had a larger pore size, and a looser and rougher structure than that of the top side. By using a microfluidics-based in vitro wound healing model, we revealed that the bottom side of the BC film can better promote the migration of cells to facilitate wound healing. Furthermore, the full-thickness skin wounds on Wistar rats demonstrated that, compared with gauze and the top side of the BC film, the wound covered by the bottom side of the BC film showed faster recovery rate and less inflammatory response. The results indicate that the platform based on the microfluidic chip provide a rapid, reliable, and repeatable method for wound dressing screening. As an excellent biomaterial for wound healing, the BC film displays different properties on different sides, which not only provides a method to optimize the biocompatibility of wound dressings but also paves a new way to building heterogeneous BC-based biomaterials for complex tissue engineering.

Minimally invasive stabilization using screws and cement for acetabular metastatic tumor: a case report.

BACKGROUND: The aim of this case report is to evaluate minimally invasive stabilization using screws and cement for acetabular metastatic tumor and summarize the indications and contraindications for minimally invasive stabilization of acetabular metastatic tumors with screw and cement techniques. CASE PRESENTATION: Under imaging guidance, a patient with acetabular metastatic tumor was treated with hollow screw combined with bone cement fixation. Ischial screw, ascending branch screw, and anterior and posterior screws were inserted to firmly fix the anterior and posterior column of the acetabulum. At the same time, the third screw connected the anterior and posterior columns together, combined with bone cement into the fracture site to further increase local stability and resist bone defects caused by local tumor osteolysis. The patient was a 52-year-old Uygur male. Herein, we summarize his clinical symptoms and operation. Differences in visual analog scale and walking function (Musculoskeletal Tumor Society) before operation and at 2 months, 6 months, and 12 months after operation were compared. RESULTS: Postoperative complications and tumor progression were recorded. The patient was followed up for 16 months, and the operative time was 60 minutes. In total, 20 ml of bone cement was injected into the acetabular posterior column and the top of the acetabulum. VIsual analog scale score was 8 before operation, 3 at 2 months, 3 at 6 months, and 2 at 12 months after operation. Musculoskeletal Tumor Society function was 13 before operation, 23 at 2 months, 25 at 6 months, and 26 at 12 months after operation. During follow-up, no cement leakage, fever, hip nerve injury, pulmonary embolism, or imaging findings of further destruction of the acetabulum and surrounding bone were noted. CONCLUSION: This case report shows that the treatment of acetabular metastatic cancer with minimally invasive stabilization using screws and cement under the C arm can effectively relieve pain and enhance the strength of the pelvis, and is innovative and feasible.

A rapid and high-throughput multiplex genetic detection assay for detection, semi-quantification and virulence genotyping of Helicobacter pylori in non-invasive oral samples.

Aim: This study established a high-throughput multiplex genetic detection assay (HMGA) for rapid identification, semi-quantification and virulence analysis of Helicobacter pylori directly from the clinical non-invasive oral samples. Methods: The gastric mucosa and oral samples were collected from 242 patients in Shanghai from 2021 to 2022. All the samples were detected by routine clinical tests for H. pylori and Sanger sequenced for inconsistent results. A new multiplex PCR assay providing results within 4 hours was designed and optimized involving fluorescent dye-labeled specific primers targeted 16S rRNA gene, semi-quantitative gene ureC and 10 virulence genes of H. pylori. Semi-quantification was carried out by simulating the serial 10-fold dilutions of positive oral samples, and the H. pylori loads in different clinical samples were further compared. The mixed plasmids of virulence genes vacA s1, vacA m1 and vacA m2 were used to evaluate the performance on different genotypes. The consistency of 10 virulence genes in gastric mucosa, saliva, mouthwash and dental plaque of H. pylori-positive patients was compared. Results: The non-invasive HMGA was highly specific for detection of all 12 targets of H. pylori and human internal reference gene ß-globin, and the sensitivity to all target genes could reach 10 copies/µL. Compared with routine clinical tests and sequencing, non-invasive HMGA has a high level (>0.98) of sensitivity, specificity, accuracy, PPV, NPV and kappa coefficient for direct detection of H. pylori in oral samples. Moreover, by detecting peak area levels of ureC, it was confirmed that the H. pylori loads in gastric mucosa were significantly higher than those of the three kinds of oral samples (p<0.05). We also found that 45.0% (91/202) of patients had different H. pylori virulence genes in different oral samples. The concordance of positive detection rates of each virulence gene between saliva and gastric mucosa was more than 78% (p<0.05). Conclusion: The non-invasive HMGA proved to be a reliable method for the rapid H. pylori identification, semi-quantification and detection of 10 virulence genes directly in oral samples, providing a new idea for non-invasive detection of H. pylori.

Spatiotemporal cluster patterns of hand, foot, and mouth disease at the province level in mainland China, 2011-2018.

Although three monovalent EV-A71 vaccines have been launched in mainland China since 2016, hand, foot, and mouth disease (HFMD) still causes a considerable disease burden in China. Vaccines' use may change the epidemiological characters of HFMD. Spatial autocorrelation analysis and space-time scan statistics analysis were used to explore the spatiotemporal distribution pattern of this disease at the provincial level in mainland China. The effects of meteorological factors, socio-economic factors, and health resources on HFMD incidence were analyzed using Geodetector. Interrupted time series (ITS) was used to analyze the impact of the EV-A71 vaccine on the incidence of HFMD. This study found that the median annual incidence of HFMD was 153.78 per 100,000 (ranging from 120.79 to 205.06) in mainland China from 2011 to 2018. Two peaks of infections were observed per year. Children 5 years and under were the main morbid population. The spatial distribution of HFMD was presented a significant clustering pattern in each year (P<0.001). The distribution of HFMD cases was clustered in time and space. The range of cluster time was between April and October. The most likely cluster appeared in the southern coastal provinces (Guangxi, Guangdong, Hainan) from 2011 to 2017 and in the eastern coastal provinces (Shanghai, Jiangsu, Zhejiang) in 2018. The spatial heterogeneity of HFMD incidence could be attributed to meteorological factors, socioeconomic factors, and health resource. After introducing the EV-A71 vaccine, the instantaneous level of HFMD incidence decreased at the national level, and HFMD incidence trended downward in the southern coastal provinces and increased in the eastern coastal provinces. The prevention and control policies of HFMD should be adapted to local conditions in different provinces. It is necessary to advance the EV-A71 vaccination plan, expand the vaccine coverage and develop multivalent HFMD vaccines as soon as possible.

Late-onset Hearing Loss From Congenital Cytomegalovirus Infection After Newborn Period in a Highly Immune Population in China.

After following 141 children with likely asymptomatic congenital cytomegalovirus infection in a highly immune population in China, four children (2.8%) were found to have late-onset hearing loss. No maternal or childhood factors, except higher saliva cytomegalovirus viral load at birth (P = 0.03), were associated with increased risk of developing a hearing loss.

An emerging recombinant human enterovirus 71 responsible for the 2008 outbreak of hand foot and mouth disease in Fuyang city of China.

Hand, foot and mouth disease (HFMD), a common contagious disease that usually affects children, is normally mild but can have life-threatening manifestations. It can be caused by enteroviruses, particularly Coxsackieviruses and human enterovirus 71 (HEV71) with highly variable clinical manifestations. In the spring of 2008, a large, unprecedented HFMD outbreak in Fuyang city of Anhui province in the central part of southeastern China resulted in a high aggregation of fatal cases. In this study, epidemiologic and clinical investigations, laboratory testing, and genetic analyses were performed to identify the causal pathogen of the outbreak. Of the 6,049 cases reported between 1 March and 9 May of 2008, 3023 (50%) were hospitalized, 353 (5.8%) were severe and 22 (0.36%) were fatal. HEV71 was confirmed as the etiological pathogen of the outbreak. Phylogenetic analyses of entire VP1 capsid protein sequence of 45 Fuyang HEV71 isolates showed that they belong to C4a cluster of the C4 subgenotype. In addition, genetic recombinations were found in the 3D region (RNA-dependent RNA polymerase, a major component of the viral replication complex of the genome) between the Fuyang HEV71 strain and Coxsackievirus A16 (CV-A16), resulting in a recombination virus. In conclusion, an emerging recombinant HEV71 was responsible for the HFMD outbreak in Fuyang City of China, 2008.

A highly sensitive quartz crystal microbalance sensor modified with antifouling microgels for saliva glucose monitoring.

Saliva glucose detection based on quartz crystal microbalance (QCM) technology has become an important research direction of non-invasive blood glucose monitoring. However, the performance of this label-free glucose sensor is heavily deteriorated by the large amount of protein contaminants in saliva. Here, we successfully achieved the direct detection of saliva glucose by endowing the microgels on the QCM chip with superior protein-resistive and glucose-sensitive properties. Specifically, the microgel networks provide plenty of boric acid binding sites to amplify the signals of targeted glucose. The amino acid layer wrapped around the microgel and crosslinking layer can effectively eliminate the impact of non-specific proteins in saliva. The designed QCM sensor has a good linearity in the glucose concentration range of 0-40 mg L-1 in the pH range of 6.8-7.5, satisfying the physiological conditions of saliva glucose. Moreover, the sensor has excellent ability to tolerate proteins, enabling it to detect glucose in 50% human saliva. This result provides a new approach for non-invasive blood glucose monitoring based on QCM.

The development of an antifouling interpenetrating polymer network hydrogel film for salivary glucose monitoring.

Owing to its rapid response and broad detection range, a phenylboronic acid (PBA)-functionalized hydrogel film-coated quartz crystal microbalance (QCM) sensor is used to non-invasively monitor salivary glucose in diabetic patients. However, nonspecific protein adsorption on the PBA-functionalized hydrogel film can cause dramatic loss of sensitivity and accuracy of the sensor. A traditional zwitterionic polymer surface with ultra-low protein fouling can hinder the interaction of PBA in the hydrogel matrix with glucose molecules owing to its steric hindrance, resulting in poor glucose sensitivity of the sensor. Herein, we developed a novel hydrogel film that enhanced the antifouling properties and sensitivity of the QCM sensor by infiltrating a glucose-sensitive monomer (i.e., PBA) into a zwitterionic polymer brush matrix to form an interpenetrating polymer network (IPN). The IPN hydrogel film could minimize the glucose sensitivity loss since the antifouling polymer distributed in its matrix. Moreover, a stable hydration layer was formed in this film that could prevent water from transporting out of the matrix, thus further improving its antifouling properties and glucose sensitivity. The experimental results confirmed that the IPN hydrogel film possessed excellent resistance to protein fouling by mucin from whole saliva with reductions in adsorption of nearly 88% and could also enhance the glucose sensitivity by nearly 2 fold, compared to the PBA-functionalized hydrogel film. Therefore, the IPN hydrogel film provides improved antifouling properties and sensitivity of the QCM sensor, which paves the way for non-invasive monitoring of low concentrations of glucose in saliva.

Ultrasensitive Poly(boric acid) Hydrogel-Coated Quartz Crystal Microbalance Sensor by Using UV Pressing-Assisted Polymerization for Saliva Glucose Monitoring.

Quartz crystal microbalance (QCM) has attracted extensive attention in the field of biological analysis and detection because of its high sensitivity, fast response, real-time measurement, good operability, and low-cost production. However, to detect the trace amounts of small molecules, such as low-concentration saliva glucose under physiological conditions, is still a major challenge. Herein, the surface of a QCM chip was coated with a poly(boric acid)-based hydrogel using UV pressing-assisted polymerization to obtain a simple device for glucose detection. The designed QCM sensor shows a record-low detection limit of glucose (3 mg/L at pH 7.5), which is ∼30 times lower than that of sensors fabricated by conventional surface initiation-spin coating. The outperformance of the poly(boric acid) hydrogel-coated QCM sensor is probably due to the uniform and compact microstructure, as well as the presence of sufficient glucose-binding sites resulting from the hydrogel coating generated by UV pressing-assisted polymerization. This method provides an important solution to detect the trace amounts of small organic molecules or ions and has the potential to push forward the practical applications of QCM sensors.

Viral Loads in Congenital Cytomegalovirus Infection From a Highly Immune Population.

Among newborns with congenital cytomegalovirus (CMV) infection from China, there was no difference in CMV viral load in saliva specimens dried and stored at room temperature compared with those kept wet and stored cold, even after longer storage time for the former than the later (74 vs 58 days, P = .02).

Cohort study on maternal cytomegalovirus seroprevalence and prevalence and clinical manifestations of congenital infection in China.

Congenital cytomegalovirus (CMV) infection is the leading viral cause of birth defects and developmental disabilities in developed countries. However, CMV seroprevalence and burden of congenital CMV infection are not well defined in China.Cohort of newborns from 5 birthing hospitals in 2 counties of Shandong Province, China, were enrolled from March 2011 to August 2013. Dried blood spots (DBS) and saliva were collected within 4 days after birth for IgG testing for maternal seroprevalence and real-time PCR testing for congenital CMV infection, respectively.Among 5020 newborns tested for CMV IgG, 4827 were seropositive, resulting in CMV maternal seroprevalence of 96.2% (95% confidence interval [CI]:95.6%-96.7%). Of the 10,933 newborns screened for congenital CMV infection, 75 had CMV detected, resulting in an overall prevalence of 0.7% (95% CI: 0.5%-0.9%), with prevalences of 0.4% (14/3995), 0.6% (66/10,857), and 0.7% (52/7761) for DBS, wet saliva, and dried saliva specimens screened, respectively. Prevalence of congenital CMV infection decreased with increasing maternal age (0.9%, 0.6%, and 0.3% among newborns delivered from mothers aged 16-25, 26-35, and >35 years, respectively; P = 0.03), and was higher among preterm infants than full term infants (1.3% vs 0.6%, P = 0.04), infants with intrauterine growth restriction (IUGR) than those without (1.8% vs 0.7%, P = 0.03), and twins or triplets than singleton pregnancies (2.8% vs 0.7%, P = 0.04). None of the 75 newborns exhibited symptomatic congenital CMV infection, and there was no difference in clinical characteristics and newborn hearing screening results between infants with and without congenital CMV infection at birth.Congenital CMV infection prevalence was lower and the clinical manifestations were milder in this relatively developed region of China compared to populations from other countries with similarly high maternal seroprevalence. Follow-up on children with congenital CMV infection will clarify the burden of disabilities from congenital CMV infection in China.

Nanocrystalline Cellulose Improves the Biocompatibility and Reduces the Wear Debris of Ultrahigh Molecular Weight Polyethylene via Weak Binding.

The doping of biocompatible nanomaterials into ultrahigh molecular weight polyethylene (UHMWPE) to improve the biocompatibility and reduce the wear debris is of great significance to prolonging implantation time of UHMWPE as the bearing material for artificial joints. This study shows that UHMWPE can form a composite with nanocrystalline cellulose (NCC, a hydrophilic nanosized material with a high aspect ratio) by ball-milling and hot-pressing. Compared to pure UHMWPE, the NCC/UHMWPE composite exhibits improved tribological characteristics with reduced generation of wear debris. The underlying mechanism is related to the weak binding between hydrophilic NCC and hydrophobic UHMWPE. The hydrophilic, rigid NCC particles tend to detach from the UHMWPE surface during friction, which could move with the rubbing surface, serve as a thin lubricant layer, and protect the UHMWPE substrate from abrasion. The biological safety of the NCC/UHMWPE composite, as tested by MC3T3-E1 preosteoblast cells and macrophage RAW264.7 cells, is high, with significantly lower inflammatory responses/cytotoxicity than pure UHMWPE. The NCC/UHMWPE composite therefore could be a promising alternative to the current UHMWPE for bearing applications.

Surface modification of nano-silica on the ligament advanced reinforcement system for accelerated bone formation: primary human osteoblasts testing in vitro and animal testing in vivo.

The Ligament Advanced Reinforcement System (LARS) has been considered as a promising graft for ligament reconstruction. To improve its biocompatibility and effectiveness on new bone formation, we modified the surface of a polyethylene terephthalate (PET) ligament with nanoscale silica using atom transfer radical polymerization (ATRP) and silica polymerization. The modified ligament is tested by both in vitro and in vivo experiments. Human osteoblast testing in vitro exhibits an ∼21% higher value in cell viability for silica-modified grafts compared with original grafts. Animal testing in vivo shows that there is new formed bone in the case of a nanoscale silica-coated ligament. These results demonstrate that our approach for nanoscale silica surface modification on LARS could be potentially applied for ligament reconstruction.

Mesosilica-coated ultrafine fibers for highly efficient laccase encapsulation.

In this paper, we present a simple but efficient biomimetic method to encapsulate laccase on mesoporous silica-modified electrospun (ES) ultrafine fibers. Because of the mild immobilization conditions (room temperature, aqueous condition), the encapsulated laccase retained a high activity of 94%. Because of the protection from the silica layer, the laccase worked efficiently at 60 °C and retained a long-term activity in the presence of proteinase K. After recycling for 10 times the laccase still preserved 96% of its original reactivity. More remarkably, the immobilized laccase on fibers could completely recover its activity after thermal denature, while the free laccase permanently lost the activity. We also demonstrated that the laccase on silica-coated fibers exhibited an enhanced decolorization capability of Brilliant Blue KN-R (BBKN-R) as compared to the free laccase, showing its great potential for industrial applications.

Clinical features of severe cases of hand, foot and mouth disease with EV71 virus infection in China.

INTRODUCTION: Hand, foot and mouth disease (HFMD) caused by EV71 infection has become one of the major public health issues in China, which deeply affects children's health. The prevention and control of EV71 is a challenge currently because there is no safe and effective vaccine or antiviral medications available. MATERIAL AND METHODS: A case control study was conducted in a designated hospital to compare severe and mild cases of patients infected with the EV71 virus. Demographic information along with clinical features of HFMD was collected through a standardized questionnaire. Multi-factorial logistic regression was used to analyze independent associations between potential risk factors and severe HFMD. RESULTS: There were 120 cases (60 cases and 60 controls) collected. The male-to-female ratio was 1.3: 1 in the case group and 1.7: 1 in the control group. Multi-factorial logistic regression revealed that the main risk factors for severe cases were highest body temperature being ≥ 38.5°C (OR = 9.45, 95% CI: 2.07-43.11, p < 0.05), first visited a village level clinic (OR = 4.72, 95% CI: 1.15-19.45, p < 0.05), etc. CONCLUSIONS: Close surveillance combined with laboratory testing should be in place during the epidemic period of HFMD. Grass root level medical facilities and training of clinical and laboratory staff should be reinforced so that the diagnostic and treatment capacity can be improved.

An outbreak of hand, foot, and mouth disease associated with subgenotype C4 of human enterovirus 71 in Shandong, China.

BACKGROUND: An outbreak of hand, foot, and mouth disease (HFMD) included 1149 people in Linyi City, Shandong Province, China, in 2007: three children died. OBJECTIVES: To characterize the pathogens responsible for this outbreak and to analyze their genetic features. STUDY DESIGN: A total of 233 clinical specimens were collected from 105 hospitalized patients, including 11 patients with severe HFMD. Virological investigations (direct RT-PCR, viral isolation and molecular identification) and phylogenetic analysis were performed. RESULTS: Human enterovirus 71 (HEV71) was the main pathogen that caused this outbreak, based on clinical manifestations, epidemiological data, and laboratory results. Phylogenetic analysis indicated that the Shandong HEV71 isolates belonged to 3 lineages in subgenotype C4. Subgenotype C4 could be further divided into two clusters (C4a and C4b), which corresponded to two time periods. Cluster C4a HEV71 has been the predominant virus circulating in mainland China in the past 5 years. CONCLUSIONS: The 2007 HFMD outbreak was mainly caused by HEV71 subgenotype C4 with 3 transmission chains. This virus has been continuously circulating in China since 1998. The Shandong strains co-evolved with isolates from other provinces in mainland China and neighboring countries.