Polyethylene glycol fusion repair of severed sciatic nerves accelerates recovery of nociceptive sensory perceptions in male and female rats of different strains

Successful polyethylene glycol fusion(PEG-fusion)of severed axons following peripheral nerve injuries for PEG-fused axons has been reported to:(1)rapidly restore electrophysiological continuity;(2)prevent distal Wallerian Degeneration and maintain their myelin sheaths;(3)promote primarily motor,voluntary behavioral recoveries as assessed by the Sciatic Functional Index;and,(4)rapidly produce correct and incorrect connections in many possible combinations that produce rapid and extensive recovery of functional peripheral nervous system/central nervous system connections and reflex(e.g.,toe twitch)or voluntary behaviors.The preceding companion paper describes sensory terminal field reo rganization following PEG-fusion repair of sciatic nerve transections or ablations;howeve r,sensory behavioral recovery has not been explicitly explored following PEG-fusion repair.In the current study,we confirmed the success of PEG-fusion surgeries according to criteria(1-3)above and more extensively investigated whether PEG-fusion enhanced mechanical nociceptive recovery following sciatic transection in male and female outbred Sprague-Dawley and inbred Lewis rats.Mechanical nociceptive responses were assessed by measuring withdrawal thresholds using von Frey filaments on the dorsal and midplantar regions of the hindpaws.Dorsal von Frey filament tests were a more reliable method than plantar von Frey filament tests to assess mechanical nociceptive sensitivity following sciatic nerve transections.Baseline withdrawal thresholds of the sciatic-mediated lateral dorsal region differed significantly across strain but not sex.Withdrawal thresholds did not change significantly from baseline in chronic Unoperated and Sham-operated rats.Following sciatic transection,all rats exhibited severe hyposensitivity to stimuli at the lateral dorsal region of the hindpaw ipsilateral to the injury.However,PEG-fused rats exhibited significantly earlier return to baseline withdrawal thresholds than Negative Control rats.Furthermore,PEG-fused rats with significantly improved Sciatic Functional Index scores at or after 4 weeks postoperatively exhibited yet-earlier von Frey filament recove ry compared with those without Sciatic Functional Index recovery,suggesting a correlation between successful PEG-fusion and both motor-dominant and sensory-dominant behavioral recoveries.This correlation was independent of the sex or strain of the rat.Furthermore,our data showed that the acceleration of von Frey filament sensory recovery to baseline was solely due to the PEG-fused sciatic nerve and not saphenous nerve collateral outgrowths.No chronic hypersensitivity developed in any rat up to 12 weeks.All these data suggest that PEG-fusion repair of transection peripheral nerve injuries co uld have important clinical benefits.

Antibacterial Properties of Crateva adansonii (Capparidaceae) on Strains Isolated from Chronic Wounds Diagnosed in the Commune of Ouinhi in 2021

Plants have always been used by people for therapeutic purposes. They are still the main source of therapeutic substances in developing countries. Crateva adansonii, a member of the Capparidaceae family, is a medicinal plant with antibacterial properties used in Benin. The aim of this study was to assess the efficacy of an aqueous extract of C. adansonii on bacterial strains isolated from chronic wounds in the Ouinhi population. To achieve this, the bacterial flora present in chronic wounds was identified using the Ikram method (2014) coupled with the API Remoel One method. The antibacterial properties of the aqueous extract of C. adansonii on the microbial strains isolated were then assessed by determining the Inhibition Diameters (ID), the Minimum Inhibitory Concentrations (MIC) and finally the Minimum Bactericidal Concentrations (MBC). A total of eighty (80) strains were isolated and identified on the basis of morphological, cultural and biochemical characteristics. The species S. Aureus species accounted for the largest proportion (67.5%). Other species such as Listeria sp, Pseudomonas proteus, S. epidermidis and Bacillus cereus, Citrobacter freundii, Steno maltophila;Axin calcoaceticus, E. coli, K. pneumonia, Lem. richardii, Salmonella paratyphi A, Salmonella sp, Shigella sp were determined in variable proportions. At a concentration of 10 mg/ml, only S. aureus was sensitive to contact with the extract. However, at 20 mg/ml, 89% of strains were sensitive and 11% very sensitive. The highly sensitive strains are Salmonella sp and E. coli. The Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) are 20 mg/ml and 40 mg/ml respectively. The MBC/MIC ratio of the aqueous mixture of Crateva adansonii (Capparidaceae) varied from 1.2 to 2, with a bactericidal effect on 100% of the strains tested.

HIV-1 Transmission among Injecting Drug Users is Principally Derived from Local Circulating Strains in Guangxi, China

Objective The mode of human immunodeficiency virus(HIV) transmission via injection drug use(IDU)still exists, and the recent shift in IDU-related transmission of HIV infection is largely unknown. The purpose of this study was to analyze the spatiotemporal sources and dynamics of HIV-1 transmission through IDU in Guangxi.Methods We performed a molecular epidemiological investigation of infections across Guangxi from2009 to 2019. Phylogenetic and Bayesian time-geographic analyses of HIV-1 sequences were performed to confirm the characteristics of transmission between IDUs in combination with epidemiological data.Results Among the 535 subjects, CRF08_BC(57.4%), CRF01_AE(28.4%), and CRF07_BC(10.7%) were the top 3 HIV strains;72.6% of infections were linked to other provinces in the transmission network;93.6% of sequence-transmitted strains were locally endemic, with the rest coming from other provinces,predominantly Guangdong and Yunnan;92.1% of the HIV transmission among people who inject drugs tended to be transmitted between HIV-positive IDUs.Conclusion HIV recombinants were high diversity, and circulating local strains were the transmission sources among IDUs in Guangxi. However, there were still cases of IDUs linked to other provinces.Coverage of traditional prevention strategies should be expanded, and inter-provincial collaboration between Guangxi, Yunnan, and Guangdong provinces should be strengthened.

Analysis of Population Genetic Change to Single Oospore Strains of Phytophthora infestans

The occurrence of sexual reproduction accelerates the population genetic variation of Phytophthora infestans and makes it more difficult to control.The systematic analysis of the differentiation of phenotype(mating type and metalaxyl sensitivity)and genotype(mtDNA haplotype and SSR genotype)of 65 single oospore strains of P.infestans was carried out in this article.Five test strains were isolated from Heilongjiang Province and Mongolia Autonomous Region.The experiment results showed that the isolation ratio of metalaxyl resistance(MR:HR)of single oospore strains produced through the cross of medium resistance and high resistant parents was 18:13;the isolation ratio of the metalaxyl resistance(S:MR:HR)of single oospore strains produced through the cross of sensitive and high resistant parents was 4:12:7.The progenies of single oospore strains produced through self-fertility parents with medium resistance were all of the medium resistance.The mating types A1:A2 was greater than 1:1 in single oospore strains of the progenies,which did not conform to the Mendel's law of inheritance.All single oospore strains of the progenies inherited mitochondrial DNA fragments from only one parent.Sexual recombination of single oospore strains was verified by using two pairs of SSR primers(Pi4B and Pi4G).At the locus of Pi4B and Pi4G in the cross of KS-37 and KS-25,the separation frequencies of allele were 19:12 and 14:17,respectively.They produced two new genotype strains.This study could provide a basis for formulating disease control strategies.

Isolation,Screening and Identification of Cellulose Decomposing Strains in Straw-amended Soil

[Objective]The aim was to isolate cellulose decomposing strains with high activity from straw-amended soil.[Method]Screening of CMC solid culture and shaking culture rescreening were carried out to obtain cellulose decomposing strains with high activity from the corn straw amended soil,which were analyzed by 16rDNA sequence analysis.[Result]A bacterium and a fungus with higher endonucleases activity were obtained through preliminary screening and secondary screening,a fungus with higher filter paper enzyme activity,and a bacterium（NO.5 strain） with higher of both filter paper enzyme activity and CMC enzyme activity were obtained.The result of 16S rDNA sequence analysis showed that the similarity was 100% between NO.5 strain and Bacillus subtilis.[Conclusion]NO.5 strain was identified as Bacillus subtilis.

Advances in Microbial Strains and Bedding Materials in a Deep-Litter System for Pig Breeding

The selection and compatibility of the microbial strains and bedding materials in a deep-litter system is the primary issues for this ecological breeding technology. In this paper, we analyzed and summarized the categories of microbial strains and bedding materials suitable for a deep-litter system, the fermentation properties of different microbes, the parameter requirements of bedding materials, and the fermentation process led by functional microbial flora in a deep-litter system, with the objective to provide theoretical bases and practical guidance for the promotion of deep-litter breeding method nationwide.

Development of a Test Rig for Axial Strains Measurement in Automobile Wheel

In automobile wheel application, a test rig is vital and used to simulate conditions of the wheel in service in order to affirm the safety and reliability of the wheel. The present work designed a test rig for measuring axial strains in automobile wheel. The wheel used was a five-arm wheel (6JX14H2;ET 42) and Tyre (175 × 65 R 14). Experimental (EXP) test was carried out, with a radial load of 4750 N and inflation pressure of 0.3 MPa, to measure the axil strains which were converted to maximum principal strain values and, compared with data from Finite Element Analysis (FEA) using Creo-Element/Pro 5.0 at wheel’s contact angles of 90 degree (FEA 90 deg), 40 degree (FEA 40 deg) and 30.25 degree (FEA 30.25 deg), respectively. Results show that at the wheel’s point of contact with the ground, maximum principal strain values were highest at the inboard bead seat with a value of about 5.69 × 10-4 mm/mm, followed by the values at the well of about 5.66 × 10-4 mm/mm. The value at the outboard bead seat was least at about 2.22 × 10-4 mm/mm, which was due to the presence of spikes at this location that tends to resist imposed radial loads. However, the highest mean maximum principal strain values at the locations of inboard, well and outboard, were about 2.11 × 10-4 mm/mm, 3.78 × 10-4 mm/mm and .99 × 10-4 mm/mm, respectively. With the highest single value of about 5.69 × 10-4 mm/mm, the inboard bead seat was the most strained location of the wheel. Overall results showed that all values of maximum principal strains were below the threshold value of about 1 × 10-2 mm/mm. The values obtained for EXP and FEA could be said to be in close agreement when compared with the threshold value. With this in mind, the rig is recommended for use in related experimental procedures.

Relationship between trophic component of different poplar strains and occurrence of Saperda poplnea

An experimental area of poplar was established in Songyuan of Jilin Province in 1999 for testing the resistance of different poplar stains to Saperda poplnea. Incidence of S. poplnea on ten poplar strains were investigated, and the main trophic component of branches of these poplar trees were measured and analyzed in April 2001. The results showed that there existed significant difference in population size of S. poplnea on different poplar strains, and the branches of these poplar strains have significant difference in nutrient component and content of amino acids. The population size of this pest had a significantly positive correlation with dissolvable total sugar and water content but had no significant correlation with content of total nitrogen and protein nitrogen.

Protective Efficacy of Newcastle Disease Vaccines against Prevalent Strains in Recent Years

[Objective] To investigate the protective efficacy of currently available Newcastle disease vaccines against currently prevalent strains and thus provide guidance for the application of vaccines and the prevention and control of Newcastle disease. E Method] The 6-week-old SPF chickens were respectively inoculated with five live attenuated Newcastle disease vaccines （A, B, C, D, and E） at the dose of 1-fold or 0.01-fold usage via intranasal, intraocular or oral route. After 14 d post immunization, the titers of HI antibody were detected. And all the chickens were chal- lenged by Newcastle disease virus （NDV） FEo standard strain or the isolated wild strains, NDV-2007-HB and NDV-2008-YB. The clinical symptoms of chickens were continuously observed, and the morbidity and mortality were determined. [ Resalt] After 14 d post immunization, antibodies were induced at a protective level in chickens immunized with the five vaccines. As shown by the animal experiment, the five vaccines at the dose of 1-fold or 0.01-fold usage protected all vaccinated chickens from the death caused by NDV strain, and more than 90% of vaccinated chick- ens from the death caused by NDV-2007-HB strain, while the vaccines, A, B, and C, at the dose of 0.01 -fold usage protected more than 90% of vaccinated chickens from the death caused by NDV-2008-YB strain. E Conclusion] Under laboratory conditions, the currently available Newcastle disease vaccines have better protective efficacy against the two currently prevalent NDV strains and prevent the occurrence of Newcastle disease.

Expression of cyclooxygenase-2 mRNA in drug-sensitive cell and drug-resistant strains of ovarian cancer cell lines

Objective： To investigate the expression of cyclooxygenase-2 （COX-2） mRNA in drug-sensitive cell and drugresistant clones of ovarian cancer cell lines. Methods： RT-PCR and immunocytochemistry were used to investigate the expression of cyclooxygenase-2 in 3 clones drug-sensitive and 5 clones drug-resistant ovarian cancer cell. Results： Strong COX-2 mRNA expressions were detected in 3 clones of drug-sensitive cell and weak expressions were detected in 5 clones of drug-resistant cell. The protein expression of COX-2 in drug-sensitive cell was strongly positive reaction in immunocytochemistry stain and there was a weak positive reaction in 5 clones of drug-resistant cell. Conclusion： The expression of COX-2 mRNA in drug-sensitive cell strains is much higher than that in drugresistant strains of ovarian cancer cell lines, providing a basis of the chemoprevention for ovarian cancer.

Isolation and Phylogenetic Analysis of Plant Pathogen-Inhibiting Strains from Southern Ocean

[Objective] The aim was to isolate the strains resistant to plant pathogenic fungi from Southern Ocean and study their phylogenetic relationship and antimicrobial spectrum. [Method] Agar diffusion method was adopted to screen antimicrobial strains and determine the antimicrobial spectrum. Phylogenetic relationship of the strains was analyzed by neighbor-joining method of the Mega 4.0 software. [Result] Twenty antimicrobial strains were screened from seawater of Southern Ocean collected during the 27^th Chinese Antarctic Scientific Expedition. Molecular identification and phyloge- netic analysis indicated that two antimicrobial strains were members of Pseu- domonas, two strains were members of Psychrobacter, and the other 16 trains were members of Pseudoalteromonas. The antimicrobial spectrum of four strains which had higher antimicrobial activity indicated that the strains 312, 83-1 and 195 greatly inhibited the growth of Fusarium oxysporum, Rhizoctonia solani K（Jhn, Phytophthora capsici Leonian, Verticillium dahliae, Alternaria solani, Thanatephoru scucumeris and Phomopsis asparagi （Sacc）; strain 312-1 had obvious antimicrobial effect on the six of the plant pathogens except R. solani. [Conclusion] Four strains which had higher antimicrobial effect were obtained and should be further studied for development and application.

Screening of Saccharomyces Strains Highly Producing Glutathione and Breeding of Its Ethionine-resistant Mutants

[Objective] The aim of this study was to screen Saccharomyces for glutathione over-production. [Method] Ethionine-resistant mutants were obtained through UV mutagenesis and rational screening. [Result] A high GSH-producing strain HSJB1 was isolated from soil, and the biomass for this strain by flask shaking fermentation was 3.87 g/L while the GSH yield was 91.87 mg/L. According to the morphological, physiological and biochemical characteristics of cells, this strain was primarily identified as Saccharomyces cerevisiae. An ethionine-resistant mutant YBS77 was obtained through UV mutagenesis of the original strain HSJB1, and the biomass for this strain by flask shaking fermentation was 7.60 g dry cell weight/L while the GSH yield was 211.96 mg/L. [Conclusion] The biomass of the mutant obtained by breeding is increased by 96.38% than that of the original strain, and the GSH yield of the mutant obtained by breeding is increased by 130.72% than that from the original strain, which indicates that the breeding method is feasible.

Differential degradation of crude oil (Bonny Light) by four Pseudomonas strains

Four hydrocarbon degraders isolated from enriched oil- and asphalt-contaminated soils in Lagos, Nigeria, were tested for their petroleum degradation potentials. All the isolates were identified as species of Pseudomonas. Pseudomonas putida P 11 demonstrated a strong ability to degrade kerosene, gasoline, diesel, engine oil and crude oil while P. aeruginosa BB3 exhibited fair degradative ability on crude oil, gasoline, engine oil, anthracene and pyrene but weak on kerosene, diesel and dibenzothiophene. Pseudomonas putida WL2 and P. aeruginosa MVL1 grew on crude oil and all its cuts tested with the latter possessing similar polycyclic aromatic potentials as P11. All the strains grew logarithmically with 1-2 orders of magnitude and with generation time ranging significantly between 3.07 and 8.55 d at 0.05 level of confidence. Strains WL2 and MVL1 utilized the oil substrate best with more than 70% in 6 d experimental period, whereas the same feat was achieved by P11 in 12 d period. BB3 on the other hand degraded only 46% within 6 d. Interestingly, data obtained from gas chromatographic analysis of oil recovered from the culture fluids of MVL1 confirmed near-disappearance of major peaks （including aliphatics and aromatics） in the hydrocarbon mixture.

Screening of flocculant-producing strains by NTG mutagenesis

Screening of new microorganism being able to produce efficiently flocculants was carried out. A new model for screening efficient flocculant-producing strains was designed and tested. The results showed that this model for screening efficient flocculant-producing strains is very reliable and can greatly shorten the screening period. 13 flocculant-producing strains were isolated from activated sludge by conventional method. A strain, designated as HHE6, produced the bioflocculant with the turbidity removal 98% for kaolin suspension. Six of 13 strains selected as the original strains were treated with NTG as mutagen, and five mutant strains(HHE-P7, HHE-A8, HHE-P21, HHE-P24, HHE-A26) with high flocculation efficiency was obtained by selection, which exhibited the flocculation rate for kaolin suspension above 90%. Strains HHE6, HHE-P7, and HHE-P24 were classified as Penicillium purpurogenum, HHE-P21 as Penicillium cyclopium, HHE-A26 as Aspergillus versicolor and HHE-A8 as Aspergillus fumigatus, and it is hitherto unreported for biofloccutant-producing strains of Penicillium. The growth of the six strains(HHE6, HHE-P7, HHE-A8, HHE-P21, HHE-P24, HHE-A26) had similar curves, i.e. firstly increasing rapidly, keeping relatively constant then and finally decreasing gradually with cultivation time. The production of bioflocculants by strains showed the similar pattern to strain growth.

Protective efficacy of an H5/H7 trivalent inactivated vaccine(H5-Re13,H5-Re14, and H7-Re4 strains) in chickens, ducks, and geese against newly detected H5N1, H5N6, H5N8, and H7N9 viruses

Some H5 viruses isolated in poultry or wild birds between 2020 and 2021 were found to be antigenically different from the vaccine strains(H5-Re11 and H5-Re12) used in China. In this study, we generated three new recombinant vaccine seed viruses by using reverse genetics and used them for vaccine production. The vaccine strain H5-Re13 contains the hemagglutinin(HA) and neuraminidase(NA) genes of an H5 N6 virus that bears the clade 2.3.4.4 h HA gene, H5-Re14 contains the HA and NA genes of an H5 N8 virus that bears the clade 2.3.4.4 b HA gene, and H7-Re4 contains the HA and NA genes of H7 N9 virus detected in 2021. We evaluated the protective efficacy of the novel H5/H7 trivalent inactivated vaccine in chickens, ducks, and geese. The inactivated vaccine was immunogenic and induced substantial antibody responses in the birds tested. Three weeks after vaccination, chickens were challenged with five different viruses detected in 2020 and 2021: three viruses(an H5 N1 virus, an H5 N6 virus, and an H5 N8 virus) bearing the clade 2.3.4.4 b HA gene, an H5 N6 virus bearing the clade 2.3.4.4 h HA gene, and an H7 N9 virus. All of the control birds shed high titers of virus and died within 4 days post-challenge, whereas the vaccinated chickens were completely protected from these viruses. Similar protective efficacy against H5 viruses bearing the clade 2.3.4.4 h or 2.3.4.4 b HA gene was observed in ducks and geese. Our study indicates that the newly updated H5/H7 vaccine can provide solid protection against the H5 and H7 N9 viruses that are currently circulating in nature.

Analysis of genetic relationship in mutant silkworm strains of Bom-byx mori using inter simple sequence repeat (ISSR) markers

Amplified inter simple sequence repeats （ISSR） markers were used to determine genetic relationships among mutant silkworm strains of Bombyx mori. Fifteen ISSR primers containing simple sequence repeat （SSR） motifs were used in this study. A total of 113 markers were produced among 20 mutant strains, of which 73.45% were found to be polymorphic. In selected mutant genetic stocks, the average number of observed allele was （1.7080 ± 0.4567）, effective alleles （1.5194 ± 0.3950） and genetic diversity （Ht） （0.2901 ± 0.0415）. The dendrogram produced using the unweighted pair group method with arithmetic means （UPGMA） and cluster analysis made using Nei＇s genetic distance resulted in the formation of one major group containing 6 groups separated 20 mutant silkworm strains. Therefore, ISSR amplification is a valuable method for determining the genetic variability among mutant silkworm strains. This efficient molecular marker would be useful for characterizing a considerable number of silkworm strains maintained at the germplasm center.

Protective efficacy of an H5/H7 trivalent inactivated vaccine produced from Re-11, Re-12, and H7-Re2 strains against challenge with different H5 and H7 viruses in chickens

We developed an H5/H7 trivalent inactivated vaccine by using Re-11, Re-12, and H7-Re2 vaccine seed viruses, which were generated by reverse genetics and derived their HA genes from A/duck/Guizhou/S4184/2017(H5N6) (DK/GZ/S4184/17) (a clade 2.3.4.4d virus), A/chicken/Liaoning/SD007/2017(H5N1) (CK/LN/SD007/17) (a clade 2.3.2.1d virus), and A/chicken/ Guangxi/SD098/2017(H7N9) (CK/GX/SD098/17), respectively. The protective efficacy of this novel vaccine and that of the recently used H5/H7 bivalent inactivated vaccine against different H5 and H7N9 viruses was evaluated in chickens. We found that the H5/H7 bivalent vaccine provided solid protection against the H7N9 virus CK/GX/SD098/17, but only 50–60% protection against different H5 viruses. In contrast, the novel H5/H7 trivalent vaccine provided complete protection against the H5 and H7 viruses tested. Our study underscores the importance of timely updating of vaccines for avian influenza control.

Molecular Characterization and Drug-resistance of Mycobacterium tuberculosis Strains in Xuzhou, China

To understand the genetic diversity and drug resistance status of Mycobocterium tuberculosis （M. tuberculosis） circulating in Xuzhou of China, the spacer-oligonucleotide typing （Spoligotyping） and multi-loci VNTRs （variable number tandem repeats） analysis （MLVA） were utilized for the genotyping of the isolates. Drug susceptibility test （DST） was performed by the proportion method on the Lowenstein-Jensen （L-J） medium using isoniazid, rifampicin, ethambutol, and streptomycin. By Spoligotyping, 287 M. tuberculosis isolates were differentiated into 14 clusters. Then with 15-1oci MLVA, these strains could be divided into 32 clusters, 228 genotypes. Of 15 VNTRs, 6 loci had the highly discriminatory powers, 6 loci presented moderate discrimination and 3 loci demonstrated less polymorphism. The DST results showed that 46 strains were resistant to at least one first-line anti-tuberculosis agent. There was a difference in the isoniazid resistance between Beijing and non-Beijing genotype strains. We concluded that the combination of Spoligotyping and 15 VNTR loci as the genotyping in our study was applicable for this region, the drug resistant isolates were identified, and the Beijing family was the most prevalent genotype in the rural counties of Xuzhou.

Protein Expression of BLM Gene and Its Apoptosis Sensitivity in Hematopoietic Tumor Cell Strains

Patients with Bloom syndrome （BS） show an immunodeficiency, an enhanced sister chromatid exchanges （SCEs）, a strong genetic instability and an increased predisposition to all. In order to investigate the differential expression of BLM protein in hematopoietic tumor cell strains and study the effects of BLM gene on ultraviolet （UV）- or hydroxyurea （HU）-induced apoptosis, Western blot was used to detect the expression of BLM protein in normal human bone marrow mononuclear cells and 4 kinds of hematopoietic tumor cell strains. The 4 kinds of hematopoietic tumor cells were exposed to UV light with a germicidal UV lamp or treated with 2 mmol/L hydroxyurea and the apoptotic rate was detected by using AnnexinV-FITC. The results showed that these tumor cells expressed BLM protein higher than the normal human bone marrow mononuclear cells （P〈0.01）. In the 4 hematopoietic tumor cells, BLM protein was all specially cleaved in response to UV- or HU-induced apoptosis. The increase of BLM protein expression may play an important role in the development of these tumors, and BLM proteolysis is likely to be a general feature of the apoptotic response.

Misfit strains inducing voltage decay in LiMn_(y)Fe_(1-y)PO_(4)/C

LiMn_(y)Fe_(1-y)PO_(4) is considered a promising cathode material for next-generation lithium-ion batteries(LIBs) due to its high energy density and low cost. Its energy density degradation is often ascribed to the capacity loss during cycling. However, in this study, we find that the energy density degradation mainly roots in voltage decay. We have synthesized a series of LiMn_(y)Fe_(1-y)PO_(4) /C(0.5 ≤ y ≤ 0.8) and find this voltage decay is correlated with the Mn content. A high amount Mn leads to a heavier voltage decay.In-situ X-ray diffraction(XRD) and high-resolution transmission electron microscopy(HRTEM) reveal the nature of this effect, which show a mismatch along the b-axis of-2.68%(charge) and +3.4%(discharge), a volume misfit of-4.41%(charge) and +4.54%(discharge) between Li_(x)Mn_(y)Fe_(1-y)PO_(4) and Mn_(y)Fe_(1-y)PO_(4) during phase transitions. The resultant misfit strains during Li+insertion compared to extraction result in structural degradations, such as amorphization and impurity(Mn F3) accumulation after cycling. The voltage decay can be alleviated by kinetic relaxations and recovered by a wild reannealing. This work demonstrates effective strategies to improve the energy density and cycling performance of LiMn_(y)Fe_(1-y)PO_(4) /C,providing good references for other LIB cathodes, such as the Li-rich cathodes.