In recent years, potato scab caused by pathogenic Streptomyces spp. has become widespread globally, with increasing damage severely compromising the commercial value and storability of tubers. The pathogens are transmitted through the soil and seeds of potato, while existing control technologies have demonstrated limited efficacy in preventing the colonization and spread of pathogens, which pose a critical bottleneck in the sustainable development of the potato industry. This study systematically examines the pathogen characteristics and pathogenic mechanisms, evaluates the impacts of soil nutrients and microbial community structure on disease severity, and analyzes limitations in current chemical control, biological control, and disease-resistant variety breeding approaches. We propose an integrated control strategy of disease-resistant varieties, phosphorus fertilizer reduction, fertilizer efficiency enhancement, and phosphorus-soluble antagonistic fungicides, aiming to provide novel research perspectives for achieving effective prevention and control of potato scab.
Solanum tuberosum/microbiology* ; Plant Diseases/prevention & control* ; Streptomyces/pathogenicity* ; Disease Resistance ; Fungicides, Industrial/pharmacology* ; Fertilizers ; Soil Microbiology

In recent years, potato scab caused by Streptomyces scabies is aggravating year by year, becoming an industrial problem urgently to be resolved. Screening antagonistic bacteria with good inhibitory effect and wide adaptability is the main measure to realize effective prevention and control of the disease. This study screened three strains of antagonistic bacteria DXT2-4, T2-1 and 21-14 with good inhibitory effect on S. scabies by using plate standoff test, and identified them as Bacillus altitudinis, Bacillus safensis and Bacillus pumilus, respectively, based on morphological characteristics, physiological and biochemical properties, and 16S rRNA gene sequences. DXT2-4, T2-1 and 21-14 showed the pot control efficacy of 68.83%, 48.57%, and 57.14%, respectively. The field control efficacy of the three strains was 59.48%, 34.58% and 51.75% in Hulun Buir, Inner Mongolia Autonomous Region and 55.14%, 36.05%, and 49.05% in Huizhou, Guangdong. The three strains could grow normally in the media with pH 1.0-13.0 and with 1%-11% NaCl, and they had inhibitory effects on Rhizoctonia solani, Verticillium dahliae, Alternaria solani, and Fusarium oxysporum. The indole-3-acetic acid yields of DXT2-4, T2-1, and 21-14 were 2.23, 1.11, and 1.67 mg/L, respectively. DXT2-4 and 21-14 demonstrated strong abilities to solubilize phosphorus. The optimal carbon source, nitrogen source, and inorganic salt for fermentation of strain DXT2-4 were 2% molasses+2% corn starch, 2% soybean meal, and 0.3% MgSO₄·7H₂O, respectively. These findings suggest the three strains of bacteria can efficiently inhibit the growth of S. scabies and have strong environmental adaptability. Particularly, DXT2-4 has the best effects of inhibiting the disease and promoting plant growth, showing a high development value and broad application prospects, this is of great significance for promoting sustainable potato production and ensuring the environmentally sound utilization of resources.
Streptomyces/metabolism* ; Fermentation ; Plant Diseases/prevention & control* ; Solanum tuberosum/growth & development* ; Bacillus/growth & development* ; Antibiosis

Purpose To explore the diagnostic efficiency of ultrasound(US)combined with contrast-enhanced ultrasound(CEUS)in breast lesions and to analyze the related factors affecting the diagnostic accuracy.Materials and Methods From January 2022 to February 2023,the clinical data and ultrasound images of 784 patients who underwent breast US and CEUS examination with definite pathological results were retrospectively collected in the First Medical Center of the PLA General Hospital.The diagnostic efficacy of US combined with CEUS in benign and malignant breast lesions was analyzed,respectively.The independent risk factors for diagnostic errors were analyzed via Logistic regression.Results The sensitivity,specificity and accuracy of US combined with CEUS in the diagnosis of benign and malignant breast lesions were 89.2%,84.4%and 88.7%,respectively.The area under the receiver operating characteristic curve was 0.932.The results of multivariate Logistic regression analysis showed that the diagnosis error rate increased when the lesions were non-mass type(odds ratio,OR=1.927,P=0.047),complex cystic and solid(OR=3.729,P=0.000),and high-enhanced CEUS(OR=1.937,P=0.023),while the diagnosis error rate decreased when the lesions were large(OR=0.688,P=0.004)and with US-detect suspicious lymph node(OR=0.143,P=0.011).Conclusion When the breast lesions are non-mass type,complex cystic and solid lesions and hyper-enhancement,the diagnosis error rate of US combined with CEUS increased.It is necessary to further explore the enhancement patterns of different lesions.

? carotene could decrease significantly the ear index and the quantity of Evan' s blue exudation that were skin photosensitive side actions in mice treated by photodynimic therapy ( PDT ) . The PGE 1 content in skin and the histamine content in skin and blood of mice were remarkably raised by raised by PDT. For example, the PGE 1 content in hematoporphyrin derivative group was 6.4 fold greater than that of control group. The PGE1 and histamine cotents were obviously decreased to nearly normal level by pretreatment with ? carotene. The results indicated that ? carotene can antagonise the skin photosensitive side action induced by PDT and the action was related to the decrease of PGE1 and histamine content in skin of mice. The cyclo-oxidase inhibitor indomethacin and the H1 receptor blocker benadryl could also decrease ear index and the quantity of Evan' s blue exudation

The pharmacokinetics and content of 3H11-8H-HPD in tumor, liver, skin and muscular of tumor-bearing nude mice were reported and compared with free 3H-H'PD. The conjugated molar ratio of 3Hll-3H-HPD was 1 : 27. The 97% antibody activity of conjugate was retained. After 3Hll-3H-HPD or 3H-HPD iv into tumor-bearing nude mice, the pharmacokinetics parameter of blood-drug concentration indicated that the T1/2 of conjugate group was longer than that of 3H-HPD, the elimination rate constant ( Kel ) of conjugat group was larger than that of 3H-HPD group, but the aparent volume of distribution ( Vd ) of the former was less than that of the latter. Tissue distribution study reveald that the radioactivity in tumor tissue of conjugate was increased average 0.9 fold than that of 3H-HPD group. Tumor/liver ratio in both 3Hll-3H-HPD group and 3H-HPD group were 0.66 ? 0.24 and 0.42?0.20, respectively. Contents of 3Hll-3H-HPD in skin or muscular were decreased average 1 fold than that of free 3H-HPD, respectively. The study result was shown the pharmacokinetics characteristic of large molecule conjugate and the targeting action of monoclonal antibody.