Detection methods for antibiotics in wastewater: a review.

Antibiotics are widely used as fungicides because of their antibacterial and bactericidal effects. However, it is necessary to control their dosage. If the amount of antbiotics is too much, it cannot be completely metabolized and absorbed, will pollute the environment, and have a great impact on human health. Many antibiotics usually left in factory or aquaculture wastewater pollute the environment, so it is vital to detect the content of antibiotics in wastewater. This article summarizes several common methods of antibiotic detection and pretreatment steps. The detection methods of antibiotics in wastewater mainly include immunoassay, instrumental analysis method, and sensor. Studies have shown that immunoassay can detect deficient concentrations of antibiotics, but it is affected by external factors leading to errors. The detection speed of the instrumental analysis method is fast, but the repeatability is poor, the price is high, and the operation is complicated. The sensor is a method that is currently increasingly studied, including electrochemical sensors, optical sensors, biosensors, photoelectrochemical sensors, and surface plasmon resonance sensors. It has the advantages of fast detection speed, high accuracy, and strong sensitivity. However, the reproducibility and stability of the sensor are poor. At present, there is no method that can comprehensively integrate the advantages. This paper aims to review the enrichment and detection methods of antibiotics in wastewater from 2020 to the present. It also aims to provide some ideas for future research directions in this field.

Recent advances in morphology, aperture control, functional control and electrochemical sensors applications of carbon nanofibers.

Among many nanomaterials, electrospun carbon nanofibers (CNFs) have become one of the hot spots in nanoscience research because of their interesting physicochemical and biological properties such as large specific surface area, easy functionalization and biocompatibility. Polyacrylonitrile（PAN) has also become the most widely used precursor fiber for CNF manufacturing. In this paper, the latest advances in the synthesis of CNF by electrospinning were reviewed, including using template method, heat treatment, coaxial spinning technology to control the morphology and aperture, as well as the functionalization of electrospinning doped with chemical substances such as heteroatoms, nanoparticles (NPs), carbon nanotubes (CNTs) and grapheme (Gr), in order to further expand its application scope. The application of electrospun CNFs as electrochemical sensing platform for toxic and harmful substances in food and environment was also briefly introduced.

Mesoporous ZnO nanosheet as gas sensor for sensitive triethylamine detection.

In this paper, mesoporous ZnO nanosheets were synthesized by the hydrothermal method using polystyrene-polyacrylic acid (PS-PAA) as the template. The morphology, structure, and composition of the samples were characterized by SEM, TEM, XRD, and XPS, and the physical properties of the samples were tested by N2 adsorption-desorption curve. The results showed that the mesoporous ZnO nanosheets presented a flower-like appearance. Each flower is composed of flake petals which consist of nanoparticles of different sizes, with a large specific surface area. Gas sensitivity test results show that the ZnO gas sensor has good triethylamine (TEA) sensing performance. Its response to 50 ppm TEA can reach 43.771, and the detection limit is as low as 1 ppm, showing the characteristics of rapid response/recovery.

Double-layer capsule of mesoporous ZnO@SnO2 for sensitive detection of triethylamine.

To overcome obstacles such as low response and poor selectivity of pure ZnO and SnO2 gas sensors, the ZnO@SnO2 sensor was synthesized by hydrothermal synthesis. The samples were characterized by XRD, XPS, SEM, HRTEM, N2 adsorption-desorption and other techniques. The results show that ZnO@SnO2 forms an n-n-type heterostructure and presents a double-layer capsule with a size of 0.5-4 µm. The results show that compared with pure ZnO and SnO2, the ZnO@SnO2 sensor exhibits a higher response (138.9) to 50 ppm triethylamine (TEA) at 152°C, which is 19.56 times that of the pure ZnO sensor and 21.7 times that of the SnO2 sensor. It has a short response/recovery time (11/11 s), excellent selectivity and cycling stability. Compared with other volatile organic compounds or gases, it has higher selectivity for TEA detection.

Norovirus outbreaks in Fengtai District, Beijing, China, 2014.

Norovirus (NoV) is the most common cause of non-bacterial acute gastroenteritis (AGE) outbreaks worldwide. Eight NoV outbreaks in the Fengtai District of Beijing City, China, were identified in 2014. Samples were collected from the eight outbreaks, and 73 out of 119 samples from cases and 10 out of 59 samples from the close contacts were positive for NoVs. The genotypes were determined by sequencing analysis. Six different GII genotypes, including GII.2, 4, 6, 7, 8, 14, and 17 were found, and GII.4 was not the local major epidemic genotype in the present study. Enhanced strain surveillance is necessary for future NoV epidemics.

An aptamerelectrochemical sensor based on functional carbon nanofibers for tetracycline determination.

Fe-Co@CNF was synthesized by electrospinning technology, and AuNPs was loaded onto Fe-Co@CNF by in-situ reduction to obtain Fe-Co@CNF@AuNPs composite material, which was used as the working electrode based on Au-S bond cooperation. The tetracycline electrochemical sensing interface Fe-Co@CNF@AuNPs@Apt was constructed by connecting mercaptoylated tetracycline (TC) aptamers on Fe-Co@CNF@AuNPs surface. The morphology and composition of Fe-Co@CNF@AuNPs composites were characterized by SEM, TEM, EDS, XRD and XPS, and the electrochemical properties of tetracycline were evaluated by CV and DPV. The results showed that the addition of Fe and Co did not destroy the structure of the original carbon nanofibers, and their synergistic effect enhanced the electrocatalytic performance, effective electrode area and electron transfer ability of carbon nanofibers. AuNPs are evenly distributed over the fibers, which effectively improves the electrical conductivity of the material. Under the optimal conditions, the theoretical detection limit of tetracycline was 0.213 nM, and the linear detection range was 5.12-10 mM, which could successfully detect tetracycline in milk.

Antibody-assisted MIL-53(Fe)/Pt-based electrochemical biosensor for the detection of the nicotine metabolite cotinine.

Antibody-assisted MIL-53(Fe)/Pt was used as an electrochemical biosensor, and a rapid detection method for analysing cotinine content in smokers' saliva was developed based on this sensor. In this sensor, Pt-modified MIL-53(Fe) was modified as an electrode material onto the surface of the working electrode. The amino group was activated with glutaraldehyde and antibodies to cotinine were modified onto the surface and closed with 1% BSA. Cyclic voltammetry (CV), differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS) were used to study the electrode assembly and cotinine detection. The DPV results showed an ideal linear relationship between the current value and the logarithm of the concentration. The detection limit was 0.0092 ng/mL. It has good selectivity and cycling stability. The proposed Abs-MIL-53(Fe)/Pt can effectively and sensitively detect cotinine in saliva and has promisingapplications.

Asymptomatic Norovirus Infection Among Children in Kindergartens and Primary Schools - Beijing Municipality, China, 2021.

What is already known about this topic?: Children in kindergartens and primary schools are the high-incidence groups of norovirus acute gastroenteritis. However, asymptomatic norovirus infection among them is seldom reported. What is added by this report?: The norovirus positive rate was 3.48% among asymptomatic children in kindergartens and primary schools in Beijing Municipality in June 2021, the most common genotype was GII.4 Sydney, and no acute gastroenteritis outbreak was reported over the study period. What are the implications for public health practice?: The asymptomatic norovirus infection was relatively low among kindergarten children and primary school students in summer. Norovirus genotypes in asymptomatic children were similar to those circulating in the symptomatic cases. Asymptomatic norovirus infection may play a limited role in causing acute gastroenteritis outbreaks.

[Esthetic evaluation of Cerec 3D anterior crowns].

OBJECTIVE: To observe the short-term effect of clinical application of Cerec 3D anterior crowns. METHODS: A total of 16 patients were restored with 31 Cerec 3D anterior crowns. All restorations were stained before cementation. The evaluation started 1 week after luting. The restorations were examined in accordance with the modified US Public Health Service (USPHS) criteria at baseline and every 6 - 12 months. RESULTS: The observation period of 31 Cerec 3D anterior crowns varied from 8 to 33 months. The mean observation period was 22 months. All restorations scored A or B by modified USPHS standard. And 22 out of 31 restorations scored A for all criteria while 8 restorations scored B in color matching. Slight differences of translucency and chroma could be observed. Between baseline and follow-up examinations, insignificant shift from A-to B-rating occurred. CONCLUSION: Cerec 3D anterior crowns may achieve favorable short-term esthetic effects.

Surface Plasmon Resonance (SPR) biosensor for detection of mycotoxins: A review.

Mycotoxin is one of the most important natural pollutants, which poses a global threat to food safety. However, the pollution of mold in food production is inevitable. The detection technology of mycotoxins in food production is an important means to prevent the damage of mycotoxins, so rapid detection and screening to avoid pollution diffusion is essential. The focus of this review is to update the literature on the detection of mycotoxins by surface plasmon resonance (SPR) technology, rather than just traditional chromatographic methods. As a relatively novel and simple analytical method, SPR has been proved to be fast, sensitive and label-free, and has been widely used in real-time qualitative and quantitative analysis of various pollutants. This paper aims to give a broad overview of the sensors for detection and analysis of several common mycotoxins.

Should we pay attention to recombinant norovirus strain GII.P7/GII.6?

BACKGROUND: Recombinant norovirus strain GII.P7/GII.6 has been circulating in Asia and around the world for at least 20 years, but has been responsible for relatively few outbreaks. METHODS: We used statistical analyses, real-time reverse transcription - PCR, and genome sequence analyses to investigate an outbreak of gastroenteritis, identifying the pathogen, the risk factors associated with the outbreak, and the molecular features of GII.P7/GII.6 strains. RESULTS: An outbreak of gastroenteritis was reported at a school involving 12 students and lasting 6 days, from September 13 to September 18, 2017. Epidemiological studies suggested that norovirus was transmitted from person to person and not via contaminated food or drinking water in this outbreak. Using a sequence analysis of the junction region between open reading frames 1 and 2, the pathogen was identified as a recombinant norovirus (strain GII.P7/GII.6). The full-length genome of the outbreak strain shared 86%-97% identity with those of other GII.P7/GII.6 strains. Phylogenetic trees were constructed from partial open reading frame 1 (ORF1) and ORF2 sequences from the outbreak strain and GII.P7/GII.6 norovirus sequences available in GenBank. On the ORF1 tree, the partial sequences of ORF1 were grouped into cluster A (with GII.6), cluster B (with GII.7), and a separate cluster (C), based on the GII.6 and GII.7 reference strains. The ORF2 tree showed all GII.P7/GII.6 strains formed a cluster together with GII.6 strains. Amino-acid substitutions and insertions/deletions were common in the capsid protein, especially in it's P2 and P1 domains. The outbreak was controlled within several days using appropriate measures. CONCLUSIONS: Because it may play a prominent role in future outbreaks, recombinant norovirus strain GII.P7/GII.6 should be monitored with routine surveillance.

[Effects of 16 week aerobic exercise on baPWV and ABI of middle-aged and elderly patients].

OBJECTIVES: To investigate the interventional effects of 16-week aerobic exercises on the elderly's arteriosclerosis and its mechanism. METHODS: Twenty-seven elderly people with the average age of 62. 70 ±3. 26 joined a 16-week square dance/taijiquan exercise program that conducted 60 minutes each time, six times per week. Arterial stiffness and its related indexes such as systolic pressure(SBP), diastolic pressure(DBP), left brachial-ankle pulse wave velocity (L-baPWV), right brachial-ankle pulse wave velocity(R-baPWV), left ankle brachial index (L-ABI), right ankle brachial index(R-ABI), serum triglyceride(TG), total cholesterol(TC), high density lipoprotein cholesterol(HDL-c), low density lipoprotein cholesterol(LDL-c), superoxide dismutase(SOD), malondialdehyde(MDA) and glutathione peroxidase (GSH-Px) were detected at 3 time points including before exercise program, by the end of exercise for 8 weeks and 16 weeks. RESULTS: ① Compared with pre-exercise, the R-baPWV and R-ABI of the elderly people were decreased at the end of the 8th week, and the L-baPWV, RbaPWV, R-ABI and L-ABI were decreased significantly at the end of the 16th week. ②Compared with pre-exercise, SBP and DBP were declined markedly (P<0.01, P<0.05) at the end of the 8th week, SBP, DBP and pulse pressure were decreased significantly (P<0.01, P<0.05) at the end of the 16th week. ③Compared with pre-exercise, TC and LDL-c were declined markedly (P<0.01) at the end of the 8th and the 16th week, and there was no difference of the level of TG and LDL-c between pre-exercise and post-exercise. ④There was no evident difference of serum level of SOD, GSH-Px, MDA between pre-exercise and post-exercise at the end of the 8th week. Compared with pre-exercise, the level of serum SOD, GSH-Px was increased evidently while the content of serum MDA was decreased significantly (P<0.01). CONCLUSIONS: Sixteen-week aerobic exercises could reduce baPWV and ABI levels, regulate blood pressure, blood lipids and lipid peroxides levels of the elderly evidently, thus improve the controlling quality of atherosclerosis.

A Waterborne Gastroenteritis Outbreak Caused by Norovirus GII.17 in a Hotel, Hebei, China, December 2014.

Norovirus (NoV) is responsible for an estimated 90 % of all epidemic nonbacterial outbreaks of gastroenteritis worldwide. Waterborne outbreaks of NoV are commonly reported. A novel GII.17 NoV strain emerged as a major cause of gastroenteritis outbreaks in China during the winter of 2014/2015. During this time, an outbreak of gastroenteritis occurred at a hotel in a ski park in Hebei Province, China. Epidemiological investigations indicated that one water well, which had only recently been in use, was the probable source. GII.17 NoV was detected by real-time reverse-transcription polymerase chain reaction from samples taken from cases, from concentrated water samples from water well, and from the nearby sewage settling tank. Nucleotide sequences of NoV extracted from clinical and water specimens were genetically identical and had 99 % homology with Beijing/CHN/2015. All epidemiological data indicated that GII.17 NoV was responsible for this outbreak. This is the first reported laboratory-confirmed waterborne outbreak caused by GII.17 NoV genotype in China. Strengthening management of well drinking water and systematica monitoring of NoV is essential for preventing future outbreaks.