L-tyrosine is one of the 20 amino acids that make up proteins and is an essential amino acid for mammals, often used as a nutritional supplement. The conventional methods for synthesizing L-tyrosine have some problems such as the production of many by-products, high requirements for production conditions, and environmental pollution. In this study, we designed and constructed a multi-enzyme cascade for the synthesis of L-tyrosine with alanine, glutamate, ammonium chloride, and phenol as substrates. Initially, the sources of glutamate oxidase, alanine aminotransferase, and tyrosine phenol lyase were screened and analyzed, which was followed by the identification of the rate-limiting enzyme in the reaction process. A colorimetric screening method was established, and the rate-limiting enzyme DbAlaA was engineered to enhance its activity by 40.0%. Subsequently, the reaction conditions, including temperature, pH, cell concentration, and surfactant and coenzyme dosages, were optimized. After optimization, the yield of L-tyrosine reached 9.93 g/L, with a alanine conversion rate of 54.90%. Finally, a feed-batch fermentation strategy was adopted, and the yield of L-tyrosine reached 56.07 g/L after 24 h, with a alanine conversion rate of 65.22%. This study provides a reference for the whole-cell catalytic synthesis of L-tyrosine and its industrialization.
Tyrosine/biosynthesis* ; Escherichia coli/metabolism* ; Tyrosine Phenol-Lyase/genetics* ; Multienzyme Complexes/metabolism* ; Fermentation

Guided by the concept of quality by design(QbD), this study optimizes the calcination and quenching process of calcined Magnetitum and establishes the XRD characteristic spectra of calcined Magnetitum, providing a scientific basis for the formulation of quality standards. Based on the processing methods and quality requirements of Magnetitum in the Chinese Pharmacopoeia, the critical process parameters(CPPs) identified were calcination temperature, calcination time, particle size, laying thickness, and the number of vinegar quenching cycles. The critical quality attributes(CQAs) included Fe mass fraction, Fe~(2+) dissolution, and surface color. The weight coefficients were determined by combining Analytic Hierarchy Process(AHP) and the criteria importance though intercrieria correlation(CRITIC) method, and the calcination process was optimized using orthogonal experimentation. Surface color was selected as a CQA, and based on the principle of color value, the surface color of calcined Magnetitum was objectively quantified. The vinegar quenching process was then optimized to determine the best processing conditions. X-ray diffraction(XRD) was used to establish the characteristic spectra of calcined Magnetitum, and methods such as similarity evaluation, cluster analysis, and orthogonal partial least squares-discriminant analysis(OPLS-DA) were used to evaluate the quality of the spectra. The optimized calcined Magnetitum preparation process was found to be calcination at 750 ℃ for 1 h, with a laying thickness of 4 cm, a particle size of 0.4-0.8 cm, and one vinegar quenching cycle(Magnetitum-vinegar ratio 10∶3), which was stable and feasible. The XRD characteristic spectra analysis method, featuring 9 common peaks as fingerprint information, was established. The average correlation coefficient ranged from 0.839 5-0.988 1, and the average angle cosine ranged from 0.914 4 to 0.995 6, indicating good similarity. Cluster analysis results showed that Magnetitum and calcined Magnetitum could be grouped together, with similar compositions. OPLS-DA discriminant analysis identified three key characteristic peaks, with Fe_2O_3 being the distinguishing component between the two. The final optimized processing method is stable and feasible, and the XRD characteristic spectra of calcined Magnetitum was initially established, providing a reference for subsequent quality control and the formulation of quality standards for calcined Magnetitum.
X-Ray Diffraction/methods* ; Drugs, Chinese Herbal/chemistry* ; Quality Control ; Particle Size

With the rapid development of competitive sports, the incidence of anterior cruciate ligament (ACL) injury is on the rise. Such injuries may shorten athletes′ career and lead to other long-term adverse consequences. Although athletes generally recover well after ACL reconstruction, many still struggle to return to their pre-injury performance levels. Advances in the understanding of ACL anatomy and injury mechanisms, along with the evolution of surgical techniques and rehabilitation methods, have provided more individualized and tailored options for athletes following ACL injuries. However, there is currently no consensus in China regarding surgical and rehabilitation strategies for competitive athletes aiming to return to sports after ACL injuries. To this end, the Sports Medicine Committee of the Chinese Research Hospital Association and the Editorial Board of the Chinese Journal of Trauma jointly formulated the Expert consensus on surgical treatment and rehabilitation for competitive sports athletes returning to sports after anterior cruciate ligament injury ( version 2025), and presented 14 recommendations covering surgical indications, preoperative rehabilitation, surgical timing, surgical strategies and postoperative rehabilitation strategies, aiming to improve the surgical treatment and rehabilitation system for ACL injuries in competitive athletes and facilitate their return to high-level sports performance after injury.

Due to the poor ionization efficiency and the weak mass spectrometry(MS)intensity of weakly polar substances,direct analysis using the traditional electrospray ionization mass spectrometry(ESI-MS)is a big challenge.In this study,a novel rapid on-site detection method of four prohibited sex hormones in cosmetics was proposed using online derivatization strategy coupled with a miniature mass spectrometer.The target substances in the samples were extracted by a custom-made polyaniline/multi-walled carbon nanotube solid-phase microextraction(SPME)probe.The stirring speed was 200 r/min,the extraction temperature was 40℃,and the extraction time was 2 min.A pulled dual-channel θ borosilicate glass capillary emitter was used as the nano-ESI ion source.The SPME probe was inserted into the channel containing methanol in theθborosilicate glass capillary.When the spray voltage was applied,the four sex hormones were desorbed and formed spray microdroplets,which then collided with the hydroxylamine microdroplets generated from the other channel.The microdroplets of reaction product entered into the miniature mass spectrometer for direct analysis.The limits of detection(LOD)and limits of quantification(LOQ)for the four sex hormones were 10-20 ng/mL and 20-50 ng/mL,respectively.The recoveries were from 84.6%to 107.8%with the relative standard deviations(RSD)from 4.1%to 11.6%.Compared to detection without derivatization,the MS signals of the four target substances were increased by 3 to 15 times.This method was simple,rapid,highly efficient and sensitive,and suitable for on-site rapid analysis of weakly polar sex hormones in cosmetics.

With the rapid development of competitive sports, the incidence of anterior cruciate ligament (ACL) injury is on the rise. Such injuries may shorten athletes′ career and lead to other long-term adverse consequences. Although athletes generally recover well after ACL reconstruction, many still struggle to return to their pre-injury performance levels. Advances in the understanding of ACL anatomy and injury mechanisms, along with the evolution of surgical techniques and rehabilitation methods, have provided more individualized and tailored options for athletes following ACL injuries. However, there is currently no consensus in China regarding surgical and rehabilitation strategies for competitive athletes aiming to return to sports after ACL injuries. To this end, the Sports Medicine Committee of the Chinese Research Hospital Association and the Editorial Board of the Chinese Journal of Trauma jointly formulated the Expert consensus on surgical treatment and rehabilitation for competitive sports athletes returning to sports after anterior cruciate ligament injury ( version 2025), and presented 14 recommendations covering surgical indications, preoperative rehabilitation, surgical timing, surgical strategies and postoperative rehabilitation strategies, aiming to improve the surgical treatment and rehabilitation system for ACL injuries in competitive athletes and facilitate their return to high-level sports performance after injury.

The outer membrane composed predominantly of lipopolysaccharide (LPS) is an essential biological barrier for most Gram-negative (G^-) bacteria. Lipopolysaccharide transport protein (Lpt) complex LptDE is responsible for the critical final stage of LPS transport and outer membrane assembly. The structure and function of LptDE are highly conserved in most G^- bacteria but absent in mammalian cells, and thus LptDE complex is regarded as an attractive antibacterial target. In recent 10 years, the deciphering of the three-dimensional structure of LptDE protein facilities the drug discovery based on such "non-enzyme" proteins. Murepavadin, a peptidomimetic compound, was reported to be the first compound able to target LptD, enlightening a new class of antibacterial molecules with novel mechanisms of action. This article is devoted to summarize the molecular characteristics, structure-function of LptDE protein complex and review the development of murepavadin and related peptidomimetic compounds, in order to provide references for relevant researches.

Rosuvastatin(RVS)is an excellent drug with anti-inflammatory and lipid-lowering properties in the aca-demic and medical fields.However,this drug faces a series of challenges when used to treat atherosclerosis caused by hyperhomocysteinemia(HHcy),including high oral dosage,poor targeting,and long-term toxic side effects.In this study,we applied nanotechnology to construct a biomimetic nano-delivery system,macrophage membrane(M?m)-coated RVS-loaded Prussian blue(PB)nanoparticles(MPR NPs),for improving the bioavailability and targeting capacity of RVS,specifically to the plaque lesions associated with HHcy-induced atherosclerosis.In vitro assays demonstrated that MPR NPs effectively inhibited the Toll-like receptor 4(TLR4)/hypoxia-inducible factor-1α(HIF-1α)/nucleotide-binding and oligomerization domain(NOD)-like receptor thermal protein domain associated protein 3(NLRP3)signaling pathways,reducing pyroptosis and inflammatory response in macrophages.Additionally,MPR NPs reversed the abnormal distribution of adenosine triphosphate(ATP)-binding cassette transporter A1(ABCA1)/ATP binding cassette transporter G1(ABCA1)/ATP binding cassette transporter G1(ABCG1)caused by HIF-1α,promoting cholesterol efflux and reducing lipid deposition.In vivo studies using apolipoprotein E knockout(ApoE-/-)mice confirmed the strong efficacy of MPR NPs in treating atherosclerosis with favorable bio-security,and the mechanism behind this efficacy is believed to involve the regulation of serum metabolism and the remodeling of gut microbes.These findings suggest that the synthesis of MPR NPs provides a promising nanosystem for the targeted therapy of HHcy-induced atherosclerosis.

Objective:To explore the clinical manifestations,pathological features,immunophenotype,as well as diagnosis,treatment and prognosis of patients with CD4-CD56+blastic plasmacytoid dendritic cell neoplasm(BPDCN),in order to further understand the rare disease.Methods:The clinical data,laboratory examinations and treatment regimens of two patients with CD4-CD56+BPDCN in the First Affiliated Hospital of Wannan Medical College were retrospectively analyzed.Results:The two patients were both elderly males with tumor involved in skin,bone marrow,lymph nodes,etc.Immunohistochemical results of skin lesions showed that both CD56 and CD123 were positive,while CD4,CD34,TdT,CD3,CD20,MPO and EBER were negative.Flow cytometry of bone marrow demonstrated that CD56,CD123,and CD304 were all positive,while specific immune markers of myeloid and lymphoid were negative.Two patients were initially very sensitive to acute lymphoblastic leukemia or lymphomatoid chemotherapy regimens,but prone to rapid relapse.The overall survival of both patients was 36 months and 4 months,respectively.Conclusion:CD4-CD56+BPDCN is very rare and easily misdiagnosed as other hematological tumors with poor prognosis.Acute lymphoblastic leukemia or lymphomatoid therapy should be used first to improve the poor prognosis.

Aim To investigate the protective effects of dendrobium polysaccharide(DOP)against paraceta-mol(APAP)-induced liver injury in mice and eluci-date its underlying mechanism.Methods Healthy male Kunming mice were randomly assigned to the fol-lowing groups:control group,APAP model group,low,medium,high-dose DOP intervention group(225,450,900 mg·kg-1),and DOP control group.The APAP model group was given 300 mg·kg-1 per day,the DOP intervention group was given DOP for 2 h and then APAP was given,and the remaining groups received an equal volume of normal saline daily for sev-en consecutive days.After the final administration,se-rum and liver samples from the mice were collected and tested after 20 hours.Liver morphology and liver coef-ficient were examined.Liver histopathological altera-tions and apoptosis were examined using HE staining and TUNEL staining.Additionally,medium biochemi-cal indexes were assessed in serum and liver tissue u-sing kits.The levels of oxidative stress,inflammation,and apoptosis-related proteins in liver tissue were de-termined using Western blotting.Results In the APAP model group,liver coefficient increased signifi-cantly,the number of liver vacuolar necrosis and apop-tosis cells increased,and the serum ALT and AST lev-els significantly increased.Compared with the APAP group,the liver coefficient,serum ALT and AST levels were significantly reduced,and the liver pathology was improved after DOP intervention,especially in the 900 mg·kg-1 group.The levels of oxidative stress and in-flammation in the APAP group increased,and the ex-pression of apoptosis,inflammation and oxidative stress related proteins in liver was unbalanced.DOP inter-vention,especially in the 900 mg·kg-1 group,could significantly reverse the oxidative stress,apoptosis and inflammatory response induced by APAP in liver,and increase the expression levels of Nrf2 and HO-1,but reduce the expression levels of NLRP3 and HMGB1.Conclusions The hepatoprotective mechanism of DOP is mainly due to its antioxidant and anti-inflammatory response,which may be related to the activation of Nrf2/HO-1 pathway and the inhibition of HMGB1/NL-RP3 pathway by DOP.

Protein phosphorylation modification is an important mechanism of physiological regulation that is closely related to protein biological functions. In particular, protein kinases are responsible for catalyzing the phosphorylation process of proteins, and phosphatases are responsible for catalyzing the dephosphorylation process of phosphorylation-modified proteins, which together mediate the achievement of dynamic and reversible phosphorylation modifications of proteins. Abnormal phosphorylation levels of proteins contribute to the development of many diseases, such as cancer, neurodegenerative diseases, and chronic diseases. Therefore, rational design of small molecules to regulate protein phosphorylation is an important approach for disease treatment. Based on the mechanism of protein phosphorylation regulation, small molecule drug design strategies can be classified into three types, protein kinase modulators, phosphatase modulators, and bifunctional molecules with proximity-mediated mechanism. This review emphasizes the above three small molecule design strategies for targeting protein phosphorylation regulation, including molecular design ideas, research progress and current challenges, and provides an outlook on small molecule modulators targeting protein phosphorylation modification.