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Photocatalytic antibacterial materials have been popularized and widely used in the disinfection of municipal water, the large-scale wastewater sterilization treatment of industry, and medical treatment. Their antibacterial theory has also been continuously studied and improved, and the reactive oxygen species (ROS) antibacterial mechanism has the highest acceptance by the public. The role of ROS is the main bactericidal mechanism of photocatalytic antibacterial agents, and it is also the mechanism explanation at the molecular level in the fields of organic pollutant degradation and biological pathology. ROS at an abnormal steady-state concentration attacks the organic structure outside the cell and enters the cell, causing oxidative stress reactions inside the cell and irreversible damage to the cell until apoptosis. Therefore, a systematic analysis of the production pathways, principle of action, and corresponding detection methods of active oxygen is of great importance for improving the antibacterial activity of photocatalytic antibacterial agents and exploring the antibacterial mechanism of active oxygen. First, this article introduces the production mechanism of active oxygen in photocatalytic materials and its antibacterial performance. Particularly, the modification method of constructing heterojunctions and introducing oxygen vacancies is the main way to increase active oxygen production. Second, this article summarizes the production process and mechanisms of the main ROS, such as the superoxide anion radical (·O\begin{document}${}_2^- $\end{document}), hydrogen peroxide (H2O2), singlet oxygen (1O2), and the hydroxyl radical (·OH), as well as the antibacterial process. Detection methods are summarized for four ROS, including direct methods and indirect methods as well the specific and selective reaction principle of probe molecules with ROS. Furthermore, the influencing factors of the total concentration of ROS excited by photocatalytic materials are sorted out, and a modification direction for producing ROS is proposed. This paper proposes the problems existing in the research on the action mechanism of ROS and the deficiencies in the detection methods of ROS and their specific interaction with cells. It is suggested to carefully analyze the antibacterial mechanism of ROS at the biological component level under the guidance of the generation chain of ROS and the dynamic balance system of various ROS. Finally, suggestions are made on the design and application of active oxygen antibacterial materials, and the development prospects are addressed.

Objective To estimate the accuracy and stability of capillary electrophoresis fragment analysis and clone sequencing in detecting dynamic mutations of spinocerebellar ataxia (SCA). Methods Capillary electrophoresis fragment analysis and clone sequencing were used in detecting trinucleotide repeated sequence of 14 SCA patients (3 cases of SCA2, 2 cases of SCA7, 7 cases of SCA8 and 2 cases of SCA17). Results Capillary electrophoresis fragment analysis of 3 SCA2 cases showed the expanded cytosine-adenine-guanine (CAG) repeats were 31, 30 and 32, and the copy numbers of 3 clone sequencing for 3 colonies in each case were 37/40/40, 37/38/39 and 38/39/40 respectively. Capillary electrophoresis fragment analysis of 2 SCA7 cases showed the expanded CAG repeats were 57 and 34, and the copy numbers of repeats were 69, 74, 75 in 3 colonies of one case, and was 45 in the other case. For the 7 SCA8 cases with the expanded cytosine-thymine-adenine (CTA)/cytosine-thymine-guanine (CTG) repeats of 99, 111, 104, 92, 89, 104 and 75, the results of clone sequencing were 97, 116, 104, 90, 90, 102 and 76 respectively. For 2 SCA17 cases with the short/expanded CAG repeats of 37/50 and 36/45, the results of clone sequencing were 51/50/52 and 45/44 for 3 and 2 colonies. Conclusions Although the higher mobility of polymerase chain reaction (PCR) products containing dynamic mutation in the capillary electrophoresis fragment analysis might cause the deviation for analysis of copy numbers, the deviation was predictable and the results were repeatable. The clone sequencing results showed obvious instability, especially for SCA2 and SCA7 genes, which might owing to their simple CAG repeats. Consequently, clone sequencing is not suited for detection of dynamic mutation, not to mention the quantitative criteria of dynamic mutation sequencing. DOI: 10.3969/j.issn.1672-6731.2018.03.008

Objective To investigate the clinical features and dynamic mutation of 10 cases with juvenile-onset Huntington's disease (HD). Methods The cytosine-adenine-guanine (CAG) repeats of IT15 gene were detected by polymerase chain reaction (PCR) and capillary electrophoresis in 272 individuals of 159 pedigrees with preliminary diagnosis of HD. The correlation between clinical features and expanded CAG repeats in the IT15 gene of 10 cases with juvenile-onset HD were studied carefully. Results Among 211 individuals carried expanded CAG repeats, 10 cases onset before 20 years of age. The predominant clinical manifestations were involuntary movement and cognitive impairment. The average age of onset was (12.50 ± 4.55) years, and the average CAG repeat number of IT15 gene was 63.70 ± 14.83. Pearson correlation analysis showed that the age of onset was significantly and negatively correlated with the CAG repeat number (r = - 0.865, P = 0.001). Conclusions 1) The juvenile?onset case of HD presented with different clinical features compared with adult - onset cases. The most common presentation is cognitive decline. 2) Analysis of CAG repeats of IT15 gene is necessary for the diagnosis of juvenile-onset case of HD with no family history. 3) The variability in age of onset is not completely explained by the effects of expanded CAG repeats of IT15 gene, which is more prominently for the juvenile?onset cases, therefore, it is suggested that other factors may modulate the age of onset. DOI: 10.3969/j.issn.1672-6731.2017.08.008

Objective To make the diagnosis for a patient presented with head tremor and cerebellar atrophy by integrating clinical features and accessory examination with genetic testing and to explore the interpretation of genetic testing results. Methods A 30-year-old male patient's medical information, clinical pheontype, family history and accessory examinations were collected. The next?generation sequencing (NGS) of exons in 3994 causative genes of Mendelian inheritance diseases and the family tree verification were carried out. China Human Phenotype Ontology (CHPO), Phenomizer, Ensembl and Online Mendelian Inheritance in Man (OMIM) database were used to interpret the genetic test results. Results The patient carried heterozygous mutation of spinocerebellar ataxia type 19 (SCA19) related KCND3 gene c.1057A > G (p. Ser353Gly), but his parents did not carry this mutation. The patient also carried heterozygous mutation of parkinsonism type 20 (PARK20) related SYNJ1 gene c.4436C > T (p.Thr1479Ile) which was also seen in his mother. Phenotypic similarity analysis showed the patient's phenotype was correspond with the phenotype of SCA19, and the variation locus of KCND3 gene c.1057A > G was highly conservative with homologous gene in different species. Conclusions By means of the integration of clinical phenotype with the result of genetic test, KCND3 gene c.1057A > G (p.Ser353Gly) carried in the patient is the pathogenic mutation. DOI: 10.3969/j.issn.1672-6731.2017.07.007

Background Spinocerebellar ataxia type 2 (SCA2) is an autosomal dominant genetic disease characterized by cerebellar ataxia, ophthalmoplegia, slow saccade, hyporeflexia, action tremor, cognitive decline and peripheral neuropathy. The brain MRI shows obvious atrophy of cerebellum and brainstem, indicating typical change of olivopontocerebellar atrophy. SCA2 is caused by an expanded cytosine-adenine-guanine (CAG) trinucleotide repeat in the encoding region of ATXN2. The normal CAG repeats range from 13 to 31, and ataxic phenotype occurs when the repeats are more than 34. This study focused on the clinical and imaging features of 5 SCA2 families confirmed by genetic testing. The correlation between phenotype and genotype was analyzed. Methods The pathological CAG triplet repeat expansions of SCA1-3, 6, 7, 17 and dentatorubral-pallidoluysian atrophy (DRPLA) genes were analyzed in the probands of 708 autosomal dominant SCA families and 119 sporadic SCA cases. The CAG repeat of ATXN2 gene was amplified by polymerase chain reaction (PCR) and agarose gel electrophoresis. Fragment analysis based on CEQ8000 sequencer were applied to analyze expanded alleles. Results Expanded CAG repeats of ATXN2 gene were detected in 45 probands of SCA2 families. Most of the patients manifested with the typical clinical features of SCA2 such as cerebellar ataxia, ophthalmoplegia, slow saccade and hyporeflexia. Some of them also associated with action tremor. The brain MRI showed obvious atrophy of cerebellum and brainstem. The correlation between clinical features and CAG repeat of ATXN2 gene wasstudied carefully in 5 families. Conclusion Genetic analysis provides the basis for the diagnosis of SCA2. Clinical and neuroimaging features are very helpful in the diagnosis and differential diagnosis of this disease. For the identification of cases carrying intermediate allele, it is important to combine clinical, imaging features with dynamic mutation analysis in the affected cases within the family.

Background Huntington's disease (HD) is an autosomal dominant hereditary progressive neurodegenerative disorder with a distinct phenotype characterized by chorea, dementia, cognitive and affective impairment. There are selective neural cell loss and atrophy in the caudate and putamen. Dr. George Huntington firstly described the disease accurately and insightfully, which led to a widespread recognition of the inherited chorea that now bears his name. Huntington disease gene (IT15) locus on chromosome 4p16.3, and encompasses 67 exons with a trinucleotide repeat (CAG) in the first exon. The CAG repeat length is highly polymorphic in the population and expanded on at least one chromosome of individuals with HD. Clinically, patient with HD are often onset in adulthood. Juvenile⁃onset HD is relatively rare. Adult⁃onset HD patients usually have a CAG expansion from 40 to 55 whereas those with juvenile ⁃ onset greater than 60 which are often inherited from the father. We investigated the clinical features of a juvenile⁃onset case with Huntington disease and dynamic mutation of his family. Methods The CAG repeats of IT15 gene were detected using polymerase chain reaction and capillary electrophoresis in 115 individuals with preliminary diagnosis as Huntington disease. The repeat numbers of some samples carried expanded or intermediate alleles were verified by the pMD18⁃T vector clone sequencing. Results Fragment analysis showed that one juvenile ⁃ onset case presenting with cognitive dysfunction and hypokinesis carried 15/68 CAG repeats of IT15. His father carried 17/37 and mother carried 15/17. Conclusion 1) The juvenile ⁃onset case of HD presented with different clinical features compared with adult⁃onset cases. The typical signs of adult⁃onset cases include progressive chorea, rigidity and dementia. The most common sign of juvenile⁃onset Huntington disease is cognitive decline. 2) The dynamic mutation of IT15 gene expansion of the CAG repeats in the intergenerational transmission may lead to anticipation, which is a phenomenon characterized by increasing severity and earlier onset in successive generations. The abnormal allele of the patient inherited from his father and substantially expanded between generations, which indicates the CAG repeats is more unstable in the paternal inheritance. DOI：10.3969/j.issn.1672⁃6731.2012.03.011

Objective The 3D motion capture system was used to measure the upper limb bradykinesia in Parkinson's disease (PD) to make up for the lack of artificial measurement. Methods Ninteen patients with PD (PD group) and 10 healthy subjects (control group) were recruited from June to December 2019 in Tianjin Huanhu Hospital. All the subjects completed the Unified Parkinson's Disease Rating ScaleⅢ (UPDRS⁃Ⅲ) evaluation in the room equipped with 3D motion capture system. The thumb and index finger of the subjects were fixed with reflective markers to collect motion information. In this study, only the action of finger tapping was evaluated digitally, and five parameters were extracted from the evaluation results: 1) average maximum amplitude of finger taps (amp). 2) Average finger tapping interval (intval). 3) Average zero⁃crossing occurrences of acceleration (zc). 4) Average of the forward maximum velocity (v1). 5) Average of the negative maximum velocity (v2). Using receiver operating characteristic curve (ROC) to evaluate the value of intval, zc and their combination indexes in the diagnosis of upper limb bradykinesia in PD. Results In PD group, UPDRS⁃Ⅲ score was 33.79±13.14, bradykinesia score was 13.61±5.26, upper limb bradykinesia score was 6.61±2.65, finger tapping score was 1.68±0.78. Intval (P=0.001) and zc (P=0.004) in PD group were higher than those in control group, and the difference was statistically significant. The ROC curves of intval and zc for upper limb bradykinesia showed that the AUC of them were 0.858 (95%CI: 0.743-0.973, P=0.000) and 0.799 (95%CI: 0.642-0.955, P=0.008); the sensitivity was 0.737, 0.921, and the specificity was 0.900 and 0.600, respectively. After the combination ofintvaland zc,the AUC was 0.858(95%CI:0.752-0.964, P=0.001),the sensitivity and specificity were 0.711and0.100,respectively. Conclusions The digital evaluation of upper limb bradykinesia in PD can be realized by using 3D motion capture system, which makes up for the deficiency of manual evaluation to a certain extent. The extracted parameters intval and zc have high sensitivity and specificity, which are expected to be used as characteristic indicators for early screening of PD. DOI：10.3969/j.issn.1672⁃6731.2020.08.012

Objective To investigate the effect of vocalization training in improving drooling in patients with Parkinson's disease (PD). Methods A total of 60 PD patients from August 2018 to July 2019 were randomly divided into control group (N = 30) and observation group (N = 30). The patients in control group received routine rehabilitation therapy and the observation group received routine rehabilitation therapy combined with vocalization training. All patients were treated for 4 weeks. Standardized Swallowing Assessment (SSA) was used to evaluate the swallowing function of 2 groups before and after 4⁃week training. Maximum phonation time (MPT) and maximum phonation decibel were used to evaluate the laryngeal function and vocal cord vibration. Drooling part of Unified Parkinson's Disease Rating Scale Ⅱ (UPDRS Ⅱ), Drooling Severity and Frequency Scale (DSFS) were used to evaluate drooling severity (DSFS⁃S) and frequency (DSFS⁃F). All the tests were carried out before and after 4⁃week training. Results After 4⁃week training, SSA score (P = 0.000) was lower than the score before training in both groups. MPT (P = 0.000) and maximum phonation decibel (P = 0.000) were significantly increased, moreover, drooling part of UPDRS Ⅱ score (P = 0.000), DSFS⁃S score (P = 0.000) and DSFS⁃F score (P = 0.000) were significantly decreased after 4⁃week training in both groups. Compared with control group, MPT (P = 0.010) and maximum phonation decibel (P = 0.000) were increased, and SSA score (P = 0.044), drooling part of UPDRS Ⅱ score (P = 0.020), DSFS⁃S score (P = 0.044) and DSFS⁃F score (P = 0.049) were decreased in the observation group. Conclusions Vocalization training could mitigate drooling severity and frequency of the patients with PD by improving the swallowing function. DOI：10.3969/j.issn.1672⁃6731.2019.11.014

In a cold and high humidity environment, ice and frost are easy to condense on the surfaces of aircraft, railway transportation, wind turbine blades, transmission lines and other equipment, thus reducing work efficiency, affecting the proper use of equipment, and causing huge security risks. Therefore, how to effectively delay the formation of frost on the surfaces of solid materials and promote the removal of ice has become a research hot topic in the field of high-performance materials. Conventionalde-icing methods including mechanical, chemical, and thermal de-icing have the problems of high energy consumption, excessive de-icing waste liquidlow de-icing efficiency, and easy to damage the surface of equipment, which are contrary to the sustainable development concept of “green, environmental protection, high efficiency and energy saving”. Inspired by natural biology, researchers have developed some new passive superhydrophobic anti-icing technologies, which have the advantages of low cost, low energy consumption and excellent anti-ice performance, and perform high application prospect. In this paper, for the new superhydrophobic anti-icing materials, the theoretical progress of superhydrophobic wetting of solid surfaces and the icingand anti-icing mechanism of solid surfaces were reviewed. The top-down preparation methods (laser etching, chemical etching, template method, etc.) and bottom-up preparation methods (coating technology, magnetron sputtering technology, sol-gel technology and electrodeposition technology, etc.) of superhydrophobic anti-icing surface were summarized. Finally, the limitations of superhydrophobic anti-icing materials were discussed, and their application prospect and development trend were forecasted.