FGDs and qualitative interviews of various stakeholders depict existing risk practices in the fields that may promote antimicrobial resistance. The present study revealed that widely prevalent quackery (treatment practices carried out by unauthorized persons without any recognized diploma/degree) and self-treatment by farmers, over-the-counter availability of antibiotics, low veterinarian per animal ratio, and lack of awareness among the society about the potential public health effects of antimicrobial resistance were the main risk factors for injudicious antibiotic use in the dairy sector. The present study involved a comprehensive approach targeting the stakeholders in the dairy sector and their reflections on judicious antimicrobial usage and antimicrobial resistance adapted to the dairy farming of Punjab. There is an urgent need for the advocation of policies that consider the specific challenges faced by the dairy sector to simultaneously improve access to veterinary services as well as strengthen antibiotic stewardship.The rising prevalence of antimicrobial resistance in animal foods and injudicious antibiotic use in the dairy sector pose significant threats to public health. Focus group discussions (FGDs) and key informant interviews (KIIs) were conducted with a strategic sample of four stakeholder groups (114 participants) associated with antibiotic usage in the dairy sector of Punjab. The FGDs were conducted among veterinarians ( Antimicrobial resistance (AMR) is one of the greatest public health challenges and is considered one of the next possible pandemics of the 21st century ,4. ThereIndia was ranked as one of the top 10 countries with the highest veterinary antimicrobial consumption in 2017 . The emeQualitative research approaches, such as focus group discussions (FGDs), are suitable for gaining an in-depth understanding of social issues . They acThe state of Punjab, India, is an agrarian economy, with dairying being an important source of income for farmers. The state is one of the leading milk producers in the country with the highest per capita milk availability . The daiWith this background, qualitative research on different key dairy chain stakeholders can elicit a holistic analysis of the intrinsic and extrinsic drivers of antibiotic use and how these factors influence each other to facilitate injudicious antibiotic usage and thereby AMR. Moreover, there are limited systematic studies addressing the prevailing antibiotic usage patterns and resistance in the animal husbandry sector in Indian settings. By investigating antimicrobial use through the dairy chain and how and why they are used, the “hotspots” for priority intervention and communications can be identified.The present qualitative study employed focus groups and key informant interviews with major stakeholder groups involved in veterinary services in dairy herds of Punjab, such as veterinarians, para-veterinarians, chemists, and dairy quality managers. The discussions focused on the underlying factors regarding AMU and AMR in the dairy chain of Punjab, with a broader objective of enabling the environment for behavioral change and policy intervention for judicious antibiotic usage.The study was conducted in March 2020 and May 2021. The veterinarians, para-veterinarians, chemists, and dairy quality managers were invited from three districts of Punjab, one from each of the three regions  of the state to participate in FGDs and key informant interviews (KII). The focus groups were conducted with various stakeholders in homogenous groups  where the participants were free to express their opinions and beliefs about the discussion themes.Individual permission from each participant was obtained for his/her voluntary participation in the study. The Human Ethical Research Committee, Dayanand Medical College and Hospital, Ludhiana, provided the necessary ethical approval to conduct the study under the Indian Council of Agricultural Research, Niche Area of Excellence project on ‘Antibiotic Resistance: Animal Human Interface’ (reference number DMCH/R&D/2021/7).n = 63) and para-veterinarians (n = 34) above 25 years of age and having job experience in the government sector of over two years were invited. Chemists (n = 32) involved in the dairy animal’s pharmacy and dairy quality managers (n = 16) from dairy co-operatives and large commercial dairy farms were invited. The FGDs and interviews were conducted in the Punjabi language . A total of 9 homogenous FGDs  were held with 56 veterinarians and 28 para-veterinarians, and the KIIs were held with 18 chemists and 12 dairy quality managers, respectively. The concept of theoretical saturation was used to determine the sample sizes for FGDs and KIIs [Four distinct groups, viz. practicing field veterinarians, para-veterinarians, chemists, and dairy quality managers participated in the study. The participants were selected through convenience sampling based on their required experience on the topic and availability. The inclusion criteria were meant to include participants with experience in their respective professions. Large animal field veterinarians  use of different classes of antibiotics and antibiotic combinations, and (ii) frequent occurrence of treatment failure in the field. The second core theme was the ‘risk practices for treatment failure in the field’ with three sub-themes (i) antibiotic misuse in the field, (ii) unauthorized practitioners  and self-treatment by farmers, and (iii) lack of antibiotic susceptibility testing. The third core theme was ‘knowledge on judicious antibiotic usage’, which had two subthemes: (i) source of knowledge on antibiotic usage, and (ii) extent of knowledge on antibiotic usage. The fourth core theme was ‘knowledge on antimicrobial resistance, with two subthemes: (i) awareness of AMR, and (ii) the antibiotic residues. The fifth core theme was ‘solutions for curbing the problem’ with six subthemes: (i) stopping over-the-counter availability of drugs, (ii) legal prohibition of unauthorized treatment, (iii) access and availability of veterinarians, (iv) need for field-level testing kits, (v) need for widespread awareness programs, and (vi) specialization in good managemental practices.The details of the study demographics of the participants are summarized in Theme 1: Common Disease Conditions in the Field and their TherapyVeterinarians: All the veterinarians agreed that mastitis followed by pyrexia of unknown origin (PUO) and metritis are conditions that require huge antibiotic use in the field. V3_FGD1_R1: “In case of pyrexia of unknown origin, without having any clue about the causative agent we are forced to use antibiotics.” “Mixed infections are usually prevalent; metritis or mastitis cases are accompanied by blood parasite infections in most cases”.Para-veterinarians: Regarding diseases/conditions requiring antibiotic usage prevalent in their respective areas, most of the para-veterinarians agreed upon mastitis as the most common infection followed by reproductive problems, fever, tick infections, diarrhea, and skin problems.PV3_FGD1_R1: “The maximum amount of antibiotics (around 70%) are being used in mastitis cases in my area.”Subtheme 1.1: Use of Different Classes of Antibiotics and Antibiotic CombinationsVeterinarians: As per expert estimates from the group, the enrofloxacin and gentamicin combination was the preferred choice of drug for mastitis by 70% of the veterinarians, followed by the third and higher generation of cephalosporins. In the case of metritis, the combination of intrauterine use of metronidazole and parenteral use of fluoroquinolones, such as enrofloxacin or ciprofloxacin, was used by 65% of the doctors, with the rest having a preference for oxytetracycline and ceftriaxone. Around 90% of the veterinarians agreed on using oxytetracycline in case of pyrexia of unknown origin.V43_FGD5_R3: “The mastitis cases we got to handle are previously mishandled by many hands, we are forced to use higher generation antibiotics or even in many combinations to save the life of the animal. We are left with no other options.”V15_FGD2_R1: “In repeat breeding or infertility cases also, there is much blind use of higher generation antibiotics, without knowing the actual cause behind that condition.”Para-veterinarians: The widespread use of antibiotic combinations was observed among the para-veterinarians. Overall, the majority of respondents reported the usage of enrofloxacin, a higher generation of cephalosporins, such as ceftriaxone, gentamicin, or oxytetracycline, either alone or in combination.PV13_FGD2_R2: “Enrofloxacin and gentamicin are the most effective combination for mastitis.”Chemists: The respondents reported the maximum number of sales for quinolones, third- (and higher) generation cephalosporins, tetracyclines, and aminoglycosides as compared to narrow-spectrum drugs, such as penicillin.C11_KII_R3: “In veterinary drugs, most sales are for drugs such as enrofloxacin, gentamicin, cephalosporins, and oxytetracycline.”Subtheme 1.2. Frequent Treatment Failure in the FieldVeterinarians: The frequent occurrence of treatment failure was shared by most veterinarians.V10_FGD2_R1: “In more than 30% of cases, our first line of treatment fails.” “Many a times treatment failure is observed in mastitis cases, after that I usually have to use the combination of various drugs for effective treatment.”Theme 2: Risk Practices for Treatment Failure in the FieldSubtheme 2.1. Antibiotic Misuse in the FieldVeterinarians: There was widespread use of antibiotics even in conditions that did not require their usage. Most of the veterinarians pointed toward antibiotic misuse in the field by various veterinary service providers, including para-veterinarians and illegal service providers . Many of the para-veterinarians enjoyed the status of doctors among the farmers.V11_FGD2_R1: “A big problem with antibiotic misuse in the field is that despite our efforts to complete the antibiotic course, as soon as the farmers see the improvement in the health of the animal, they feel reluctant to call us again the next day and to complete the treatment.”V8_FGD1_R1: “Terramycin (oxytetracycline) is even used as preventive measures by many farmers. Quacks know names of a few antibiotics, terramycin is famous among the quacks.”V14_FGD2_R1: “Overuse as well as underuse of antibiotics is there in the field. Dose calculation is usually based on 300 kg, but now most cows are cross-bred which weigh above 500 kg and the buffaloes weigh even more.”Para-veterinarians: All of the para-veterinarians, though legally not permitted to treat animals by administering antibiotics, were involved in the treatment of sick animals. Although they knew about bacterial and viral infections, around 90% of the para-veterinarians reported that they gave antibiotics for viral infections. Many of them were unaware of treatment durations, and most of the respondents reported stopping treatment when the animal showed improvement. The participants never had the feeling that they were not entitled to treat animals. They themselves were addressed as doctors by most of the villagers.PV23_FGD3_R3: “We are no less than veterinary doctors. Veterinary doctors have administrative works more; in fact, we do more treatment than them in villages.”PV12_FGD2_R2: “We give injections in all cases, without injections there will be no improvement in the animal”. “In indigestion and bloat also, we need injections.”Subtheme 2.1.1: Incomplete Treatment DurationVeterinarians: The quacks, farmers, and para-veterinarians were blamed by veterinarians for mishandling cases and incomplete treatment regimes.V6_FGD1_R1: “Quacks, farmers and para-veterinarians give a fixed amount of antibiotics, say 20 mL till the animal show symptoms.”Para-veterinarians: The participants were unaware of any treatment schedule and they stopped treatment once the animal stopped showing symptoms.PV9_FGD1_R1: “Ceftizoxime is one such drug which gives effect in the animal in a single shot of injection, otherwise we would have to go for two days or till the animal stop showing symptoms.”Subtheme 2.1.2. Availability of Antibiotics without PrescriptionVeterinarians: The participating veterinarians observed that as long as medicines are available over the counter in India, antibiotic abuse will continue. They reported that most of the medical shops had untrained employees that supplied medicines over the counter.V48_FGD6_R3: “The owners of medical shops used to prescribe antibiotics for animals and they even fool the farmers by forcing them to buy the high-end antibiotics to promote various pharmaceutical companies.”V41_FGD5_R3: “More than 80% of the antibiotic usage in the field is without prescription of a registered veterinarian.”Para-veterinarians: Medical shops and pharmaceutical companies were reported as the main sources of antibiotics for para-veterinarians.PV18_FGD3_R3: “We learn the treatment from our experience with doctors or our peers; moreover, we used to have good relation with chemists of our area, they used to inform us about the available new drugs.”PV2_FGD1_R1: “Cefquinome  is one such drug which is showing promising results in mastitis, I came to know about it from the chemist.”Chemists: All of the participants agreed that they routinely gave antibiotics even without prescriptions. The respondents observed that being involved in business, they could not afford to lose clients if they stopped giving antibiotics without a prescription. They pointed out that due to the lack of laws/regulations in the country, this practice will continue. Around 65% of the respondents agreed that they were unfamiliar with the dosage regime of veterinary antibiotics.C3_KII_R1: “It’s all about our client, everything is business, we can’t demand a prescription from customers.”Subtheme 2.2: Unauthorized Practitioners  and Self-Treatment by FarmersVeterinarians: The veterinarians observed that the poor farmers mostly resorted to local quacks, and even some of the progressive farmers are involved in self-treatment of the animals. The respondents pointed out the very low ratio of veterinarians per animal in the state as one of the reasons why farmers are forced to conduct self-treatment or call a quack.V12_FGD2_R1: “Even if I avoid antibiotics, farmers are not satisfied, they will call local quacks or at least purchase bolus of oral antibiotics.”V37_FGD4_R2: “The prescriptions of quacks are highly shocking, minimum 3 or 4 antibiotics along with some appetite stimulants or anti-inflammatory drugs are given.”Para-veterinarians: Even the para-veterinarians complained about the widespread mishandling of the cases by local quacks, which indicates the widespread prevalence of quackery.PV12_FGD2_R2: “We used to treat cases in our local area and our cases are complicated by local quacks.”Dairy quality managers: The respondents reported that veterinarians have a minor role in antibiotic usage in the village and that local quacks have a major role in the treatment.Subtheme 2.2.1. Lack of Availability of VeterinariansVeterinarians: The ratio of veterinarians to the animal population was reported as very low in Punjab.V16_FGD2_R1: “In Punjab, as per 20th livestock census, there are around 4,000,000 buffaloes and 2,500,000 cattle population; however, there are only 1500–2000 actively working large animal field veterinarians in the State.”V4_FGD1_R1: “Vets are always busy with administrative work or are overburdened by cases, we hardly find time for health consultancy.”V25_FGD3_R2: “There is a need to strengthen the veterinary husbandry structure in Punjab. The ratio of veterinarians per animals’ is very low. There is a need to recruit more and more veterinarians to tackle the animal treatment and welfare related issues effectively.”Para-veterinarians: The respondents reported that they are more easily accessible than veterinary doctors in the area.PV18_FGD2_R2: “We do agree that we get more cases because we are available in the village itself 24 * 7 and our government jobs fetch us more reputation and cases from the village.”Subtheme 2.2.2. Influence of Pharmaceutical CompaniesVeterinarians: The respondents observed that the practice of farmers stockpiling antibiotics is common on large farms. They observed that even the progressive farmers who could afford veterinary treatment stocked antibiotics for emergency use and were mostly influenced by the representatives of pharmaceutical companies.V43_FGD5_R3: “Costly and higher-end antibiotics, such as ceftizoxime and cefquinome are being pushed by the pharma sector. The farmers who are troubled by the frequent recurrence of mastitis usually resort to these drugs, which is influenced by the claims of the pharma companies”.Subtheme 2.3: Lack of Antibiotic Susceptibility TestingAll of the veterinarians agreed that antibiotic susceptibility testing is difficult in field conditions. None of the para-veterinarians in the present study carried out antibiotic sensitivity testing, although around 19% knew that such tests can be used to understand which antibiotic works in the given case.Subtheme 2.3.1. Lack of Available FacilitiesThe veterinarians observed that there were limited facilities in rural areas for performing these antibiotic susceptibility tests. They reported that there were no private labs in villages, and veterinary dispensaries were not equipped with such facilities.V42_FGD5_R3: “Most of us are working in veterinary dispensaries where there are no facilities for testing. Those working in veterinary polyclinics can only have lab facilities for antibiotic susceptibility testing, which are usually 50–60 km far from our hospitals.”V1_FGD1_R1: “We used to go for antibiotic susceptibility testing only for complicated cases of drug-resistant mastitis.”Subtheme 2.3.2. Extra Burden on FarmersThe veterinarians opined that antibiotic sensitivity testing facilities should be available at a subsidized rate for farmers.V10_FGD2_R2: “Most of the farmers are reluctant to pay the charges for testing, as it overburdens them apart from the treatment costs.”Subtheme 2.3.3. Need for Rapid and Accessible Testing FacilitiesThe veterinarians noted that, for the testing rates in the field to improve, there should be field-level testing diagnostic kits available that provide rapid and reliable results.V23_FGD3_R3: “The results of antibiotic sensitivity testing usually come in three days, by the time we are forced to start the therapy.”Theme 3: Knowledge of Judicious Antibiotic UsageSubtheme 3.1. Source of Knowledge on Antibiotic UsageThe most common sources of knowledge for the para-veterinarians were their peers as well as their experiences in assisting veterinarians.PV22_FGD3_R3: “We learn about which drugs to use in which conditions mostly by our experience in assisting doctors.”PV14_FGD2_R2: “We consult each other in case of treatment.”Subtheme 3.1.1. Influence of Social MediaVeterinarians: The veterinarians agreed on the marked rise of telephonic/online prescriptions since the COVID-19 pandemic. They expressed concern over the increased reliability of farmers on their social groups for treatment. They also observed a tendency of some progressive farmers to rely on internet sources for treatment.V7_FGD1_R1: “WhatsApp groups of the farmers are widely used as a discussion platform for treatment by them. This half-knowledge usually turns disastrous and complicates the case.”V11_FGD2_R1: “Such practice of treatment even through images or video calling should never be entertained”. “After COVID-19, we are forced to attend many of the cases through video calling apps.”Para-veterinarians: Most para-veterinarians who were under 35 years of age reported the influence of social media platforms in their treatments. They observed that even farmers frequently contacted them at odd hours via video calling or by clicking on images.PV22_FGD3_R3: “We have WhatsApp groups in which we share images and treatment details.”Subtheme 3.2. Extent of Knowledge on Antibiotic UsagePara-veterinarians: More than 70% of para-veterinarians were not able to differentiate between antibiotic and non-antibiotic drugs. None were able to differentiate between broad-spectrum and narrow-spectrum antibiotics. None of the participants were aware of the properties of various antibiotics and their intended actions.Chemists: None of the chemists in the study were formally trained in dispensing veterinary medicines.C13_KII_R2: “We are aware of human medicines and their dosages, though we keep stock of veterinary medicines also, we are not well versed to advise clients on the intended antibiotic use.”Theme 4. Knowledge on Antimicrobial Resistance (AMR)Subtheme 4.1. Awareness of AMRPara-veterinarians: The participants were unaware of the concept of antimicrobial resistance; around 85% said they experienced some drugs that did not show effectiveness, without a clue as to why.PV18_FGD2_R2: “Some drugs are not showing results, maybe due to the fraudulent companies who produce these.”Chemists: Many participants were unaware of the concept of antimicrobial resistance.Subtheme 4.2. Antibiotic ResiduesPara-veterinarians: The para-veterinarians in the study had no idea that humans could be harmed by drinking antibiotic-laden milk. Around 35% of the participants knew antibiotics can be excreted in milk.PV2_FGD1_R1: “Only drugs for mastitis will be excreted through milk.”Dairy quality managers: Dairy quality managers who participated in the survey were aware of antibiotic residues and their roles in antimicrobial resistance.DQM11_KII_R3: ‘I have known persons who have developed allergic reactions following consumption of milk of cow treated with strepto-penicillin.”DQM7_KII_R2: “We know that antibiotic residues may be there in milk. We cannot lose a customer unless there is strict law, we have to continue to accept milk even from treated animals.”Subtheme 4.2.1. Withdrawal PeriodVeterinarians: The veterinarians observed that withdrawal periods cannot be observed by farmers as long as farmers are not given suitable compensation for discarding milk.V36_FGD4_R2: “How can farmers dump the milk without any compensation?” “We can’t even ask a farmer with livelihood dependent on one or two cows to follow withdrawal period.”Dairy quality managers: The respondents agreed that without legal action or compensation, farmers will not observe the withdrawal period.DQM4_KII_R1: “If the milk societies in an area regularly test and penalize milk sample positive for residues, then only farmers will adhere to the withdrawal period.”Subtheme 4.2.2. Antibiotic Residue Testing ScenarioDairy quality managers: The residue testing scenario was observed as highly inadequate in field conditions and the cost was pointed out as the main issue.DQM6_KII_R2: “Nowadays there is the widespread use of antibiotic combinations in the dairy sector, residue detection of various classes requires separate kits/strips and the cost is always the main challenge behind reduced testing of milk samples.”DQM7_KII_R2: “Only specialized laboratory has chromatography facilities for residue testing, even if we manage to purchase a chromatography machine, its maintenance and functioning are also too costly.”DQM1_KII_R1: “Many times only in events of conditions such as starter failure, we used to do stringent testing.”Theme 5: Solutions for Curbing the ProblemSubtheme 5.1. Stopping over the Counter Availability of DrugsVeterinarians: The veterinarians observed that there should be a legal provision (as in foreign countries) to strictly prohibit antibiotic availability without a prescription.V19_FGD3_R2: “There is an urgent need for strict enforcement of the law that without veterinary prescription antibiotics should not be available to farmers.”Chemists: The respondents pointed out that unless a stringent law comes into enforcement, the present scenario will continue in India.Subtheme 5.2. Legal Prohibition of Unauthorized Treatment or QuackeryVeterinarians: All respondents agreed on the urgent need for legal enforcement against quackery or unauthorized use of antibiotics by unqualified professionals.V17_FGD2_R1: ‘No quacks are till now punished for their illegal practice.”Subtheme 5.3. Access and Availability of VeterinariansVeterinarians: The respondents insisted on the need to increase the availability of veterinarians–animal ratio in the state. They observed that, unless the availability of veterinary services improves at the farmers’ doorsteps, the illegal treatment will continue.V24_FGD3_R2: “There are many dispensaries in the state where the veterinarians are not available and have been functioning on the additional charge of nearby vets.”Subtheme 5.4. Need for Field-Level Testing KitsVeterinarians: All of the respondents agreed they were not performing the antibiotic sensitivity tests because of the lack of facilities. The development of rapid field-level kits can be the ideal solution for this.V14_FGD2_R1: “If there is a provision of reliable and rapid field level kits for antibiotic sensitivity, similar to that of mastitis testing kits in every veterinary dispensary, every doctor will choose an antibiotic based on its results.”Dairy quality managers: The residue testing scenario can be improved in field conditions only by the availability of cost-effective diagnostic kits.Subtheme 5.4.1. Provision of Compensation to Farmers who Adhere to the Withdrawal PeriodDairy quality managers: Antibiotic residues in milk can be reduced only if the farmers are provided with compensation for their losses.Subtheme 5.5. Need for Widespread Awareness ProgramsVeterinarians: All of the respondents in the present study were aware of the seriousness of the AMR problem and felt the dire need for educating all of society, including consumers, about the risk factors and public health threats of the problem.V4_FGD1_R1: “There is need to generate awareness among farmers and use of social media should be there to reach to the masses about the dangerous effects of antimicrobial resistance.”Subtheme 5.5.1. Need for Continuing Veterinary Education ProgramsV5_FGD1_R1: “We are not updated on latest policies or latest therapy, there is a huge need for continuing veterinary education programs.”V18_FGD2_R1: “There is much need for the ‘train the trainer’ program because without upgrading veterinarians we can’t expect the ground level changes.”Subtheme 5.6. Specialization in Good Farm Management PracticesVeterinarians: In India, there is a lack of specialization of veterinarians in farm management practices and farm biosecurity aspects.V13_FGD2_R1: “I strongly believe that mastitis is a managemental problem, many such infectious diseases can be controlled if we make the farmer aware about good farm management practices, for example, we should tell the farmers that mastitis animals should be separated from healthy herd and milked at the end of the herd milking.”V26_FGD3_R2: “Farm-level biosecurity and management is important to prevent infectious diseases.”The global action plan on AMR by the World Health Organization (WHO), the Food and Agriculture Organization (FAO), and the World Organization for Animal Health (OIE), along with India’s National Action Plans on AMR, focus on behavioral change-related interventions of the stakeholders through improved awareness and communication. Although India’s National Action Plan on AMR has been enforced to optimize antibiotic use in the country, strict enforcement still needs to be executed at the ground level . LaboratIn the present study, mastitis was reported as the most common disease condition in dairy cattle requiring antibiotic use by the participating veterinarians and para-veterinarians. This is in accordance with the results of previous studies, where more than 70% of production losses in the dairy sector of India have been attributed to mastitis ,20,30. MThe most common antibiotics prescribed by the veterinarians and para-veterinarians in the present study were the highest priority critically important antimicrobials (HPCIA) of the WHO, which mainly included quinolones, such as enrofloxacin, third- and fourth-generation cephalosporins, such as ceftriaxone, cefquinome, etc., high priority critically important antimicrobials, such as gentamicin, highly important antimicrobial, such as oxytetracycline, and aminopenicillins–beta-lactamase inhibitor combinations, such as amoxicillin-clavulanate ,35. The The widespread practice of using antibiotic combinations of HPCIA by both veterinarians and para-veterinarians was reported in the present study. Both groups blamed complications involving the illegal treatment by farmers themselves or ‘quacks’, in which they are forced to use critically important antimicrobials. The veterinarians in the present study reported that they were forced to use broad-spectrum antibiotics since they rarely treat any ‘fresh cases’ untreated by others. In concordance with the present study, most of the animal health workers of Bhutan also reported the practice of using broad-spectrum antibiotics .The present study pointed out the widely prevalent practice of self-treatment behaviors of dairy farmers in the region in accordance with earlier studies from developed nations, such as Canada, where the dairy farmers consider themselves self-reliant to diagnose and treat sick animals with antibiotics ; as wellUnlike in earlier studies where most of the para-veterinarians were aware of the concept of AMR , the majThe present discussion with the dairy quality managers revealed that there was a percentage of farmers who knew that antibiotics could harm themselves, even though they were unaware of how; however, they still sold antibiotic-laden milk to dairies. Similar findings were reported by Patnaik et al.  from PunThe present animal healthcare infrastructure is grossly inadequate to take care of the vast population of livestock/poultry in the country . The maiDirect access to veterinary drugs from the chemist’s store without a prescription was reported as the main factor that promoted the misuse of antibiotics by unauthorized persons. Chauhan et al.  reportedThe veterinarians in the present study urged the need to continue veterinary education programs or regular training for updates on antibiotics and AMR. Similar studies from Bhutan also reported the need for training programs for animal health workers in the country . The lacThe present qualitative study adopted FGDs and KIIs among various stakeholders of the dairy chain to explore the factors associated with AMU and AMR. It is well known that qualitative research addresses the nature of the phenomena rather than the measure. Thereby, qualitative research does not intend to provide a representative sample of the target population and does not lead to the same kind of inferences as quantitative methods . FurtherThe present study addresses the context of antibiotic usage in the dairy chain in the state of Punjab. The qualitative study applied a behavioral science lens to identify features that drove the injudicious use of antibiotics in the dairy sector, which could contribute to global, national, and local efforts to curb antimicrobial misuse and resistance. There is a need for the advocation of policies that consider ground-level problems of the dairy sector in Punjab, its challenges, and opportunities, to control AMR, by improving access to veterinary services and improving their prudent use via stringent regulations. There is an urgent need to improve the ratio of veterinarians per animal to strengthen the animal health care system in the region. Moreover, a deeper understanding of the drivers of injudicious antibiotic usage can also guide policy-level decisions in tropical and subtropical regions and countries with similar dairying conditions. This study also paves the way for a participatory approach, linking policymakers and researchers with relevant stakeholders involved, and focusing on need-based priority actions according to each sector and geographic area.


To explore the potential link between gut damage and proinflammatory cytokines in heroin-dependent patients.  We retrospectively analyzed and compared partial blood counts and biomarkers of intestinal injury and their potential correlations in 38 male heroin abuse patients and 29 healthy male participants. In addition, we compared and assessed proinflammatory cytokines and immune cells in 10 heroin abuse patients and 10 healthy participants. p = 0.001, p < 0.001). For predicting intestinal injury, ROC/AUC analysis showed that a cutoff of 135.7 for PLR and 0.15 for NLR yielded a sensitivity of 52% and 60% and a specificity of 82% and 86.4%, respectively . Male heroin addicts are subject to intestinal injury and present with increased proinflammatory cytokine levels.  Neutrophil counts, platelets/lymphocytes (PLR), neutrophils/lymphocytes (NLR), gut injury biomarkers, and proinflammatory cytokines, CD19+B in patients compared with healthy subjects' cells increased significantly. The number of lymphocytes, CD3 CD4 T cells, and CD3 CD8 T cells decreased in patients compared to healthy individuals. When distinguishing between heroin addicts and healthy people, ROC/AUC analysis showed that a cutoff of 142.42 for PLR and 2.18 for NLR yielded a sensitivity of 65% and 85% and a specificity of 96.5% and 89.7%, respectively ( NLR and PLR are possible indirect biomarkers for heroin dependence based on intestinal injury. Heroin and related use disorders continued to increase in U.S. adult men and women from 2002 to 2018 . In addiThe following are the inclusion criteria: (1) male heroin patients over 18; (2) complete patient data and history; (3) the last heroin abuse which was within two weeks; (4) without digestive tract diseases; (5) without common cold, fever, pain, active infections, and various diseases that may cause abnormal blood cell counts; and (6) patients which are heroin-addicted and develop intestinal damage.The following are the exclusion criteria: participants with a history of diabetes mellitus or other chronic wasting diseases, who were HIV-positive, were HCV-positive, or had any severe psychosis and bleeding disorders, or were taking anticoagulant drugs. Exclude patients with incomplete clinical information.Thirty-eight male heroin abuse patients and 29 male health participants from the First Affiliated Hospital of Yunnan and Kunming Medical University were included in the study. The 29 control male patients were healthy blood donors without any history of drug abuse, and all met the inclusion criteria except the second criterion. All study subjects provided written informed consent to the study protocol, which was approved by the Ethics Committee of Yunnan and the First Affiliated Hospital of Kunming Medical University, Kunming, China. No patients dropped out of the study.To calculate the NLR, divide the absolute neutrophil count by the absolute lymphocyte count. To calculate the PLR, divide the absolute platelet count by the absolute lymphocyte count . To calct-test or Mann–Whitney U test was used to compare two independent groups according to distribution status. Variance (ANOVA) was used to test the difference between the mean values of some parameters in the two groups. We presented correlations between two variables using Spearman's or Pearson's correlation coefficient. Finally, we analyzed the receiver operating characteristic (ROC) curve to determine the discrimination values of NLR and PLR for study subjects with or without intestinal injury. A value of p < 0.05 was considered statistically significant.Statistical analysis was conducted using IBM SPSS version 21 . Student's The characteristics of the 67 participants are presented in p = 0.007; NLR and PLR, correlation coefficient: 0.717, p = 0.002), but there were no significant differences between NLR and intestinal injury biomarkers . In addition, DAO or BT also had no significant correlation with PLR . A positive correlation was observed between NLR and PLR, and between DLC and PLR.p = 0.001) with a sensitivity of 65% and a specificity of 96.6% with a cutoff of 142.42 for PLR, and the AUC was 0.92  with a sensitivity of 85% and a specificity of 89.7% with a cutoff of 2.18 for NLR, indicating that NLR was superior to PLR as a biomarker to distinguish between heroin addicts and healthy people (p = 0.05) (p = 0.20). Considering the small sample size and intestinal injury among healthy individuals, we also included data from healthy individuals. For predicting intestinal injury in all participants, ROC/AUC analysis showed a sensitivity of 52% and a specificity of 82% when a cutoff value of 135.7 was used for PLR (p = 0.003) (p = 0.009).Based on ROC curve analysis, the area under the curve (AUC) was 0.795  . The ide= 0.003) . The ideγ , TNF-α , IL-6 , IL-8 , and IL-12 , were significantly different between the two groups  and IL-1β (patient group: 19.23 ± 18.09 versus control group: 12.01 ± 1.47) were not significantly different between the two groups, but we can see that the levels are slightly higher in heroin addicts than in healthy controls. Certain immune cells, such as CD3+CD4+ T cells  and CD19+ B cells (patient group: 24.75 ± 5.09 versus control group: 16.67 ± 1.98p = 0.0173), were significantly different between the two groups  and macrophage cells (patient group: 1.19 ± 1.18 versus control group: 0.39 ± 0.21p = 0.0504) was not significantly different between individuals in the two groups , PLR, and NLR have significant differences between healthy subjects and heroin abusers. DAO is a catabolic enzyme that is typically present in the intestinal mucosa and villi, and its serum concentration can reliably reflect the integrity and maturity of the intestinal mucosa . Human Bα, IL-1β, IL-8, IL-12, and IL-6 can lead to intestinal damage [γ promotes intestinal stem cell apoptosis and pathology [Previous studies have shown that inflammatory cytokines and immune cells are involved in intestinal damage. Inflammatory cytokines can promote bacterial association with the epithelium or might react with harmful bacteria to enhance their invasive characteristics , 33. Anil damage , 34, 35.athology , 37. Likathology . Moreoveathology . We hypoin vitro and in vivo studies are required to substantiate the findings of this study.This study also has some shortcomings. These findings may be somewhat limited due to the lack of available data for heroin addicts, and a larger study cohort would provide more accurate results. Another limitation is that we did not observe the physical intestinal injury in heroin addicts, and no relevant animal or cell experiments exist to support our study. The findings of this study have important implications for using the PLR and NLR as intestinal injury biomarkers in heroin addicts. This approach is advantageous in that it is a simple, cost-effective strategy to explore intestinal injury. Further research is necessary to explore the reliability of using the PLR and NLR, and future Intestinal damage in heroin addicts may be associated with translocation-induced production of proinflammatory cytokines by translocation of bacteria and their products. PLR and NLR have potential clinical applications as biomarkers for intestinal injury.


Prestressed steel-concrete continuous composite beam (PCCB) is a kind of beam, which makes reinforced concrete slab and steel beam bear load and coordinate deformation through connectors such as studs. Prestressed steel-concrete continuous composite beam is a kind of transverse load-bearing composite member formed by prestressed technology on the basis of ordinary composite beam. Aiming at the flexural behavior of prestressed steel-concrete continuous composite beams, a three-dimensional finite element numerical analysis model is established, and the whole process of the test is simulated based on BP neural network. The calculated results are in good agreement with the test. Using this model, the mechanical deformation performance of prestressed steel-concrete continuous composite beam is further analyzed, and the effects of some parameters  on the flexural performance of prestressed steel-concrete continuous composite beam are discussed, which provides a reference basis for engineering design. Prestressed steel-concrete continuous composite beam is a kind of transverse load-bearing composite member based on ordinary composite beam and prestressed technology. Prestressed steel-concrete continuous composite beam has the advantages of ordinary composite beam. At the same time, it increases the elastic working range of the composite beam, improves the ultimate bearing capacity of the structure, improves the fatigue and fracture performance, increases the strength reserve, improves the reliability of the beam, delays the concrete cracking, and prolongs the service life of the structure. Since the late 1980s, scholars from various countries have begun to study prestressed continuous composite beams. In 1990, Troitsky studied the theory and design of prestressed steel bridges . Other rAt present, the research of prestressed steel-concrete continuous composite beams is mostly limited to the negative moment region, and there is still a lack of systematic test and theoretical research for the whole beam. Due to the complexity of mechanical properties of prestressed steel-concrete continuous composite beams, most of the existing calculation models are mainly self-programmed, and the accuracy and stability of calculation have not been fully verified by experiments. In view of this, in order to reveal the stress and deformation mechanism of prestressed steel-concrete continuous composite beam, a three-dimensional nonlinear finite element numerical analysis model of prestressed steel-concrete continuous composite beam considering the longitudinal slip between the interface between concrete and steel beam is established by using the finite element software ANSYS. The whole process of the test is numerically simulated, and the finite element calculation results are compared with the test results. The rationality of the numerical analysis model is verified. Using this model, the mechanical performance and failure mechanism of prestressed steel-concrete continuous composite beams are analyzed and studied. The effects of some parameters  on the mechanical performance of prestressed steel-concrete continuous composite beams are discussed, which provides a reference for engineering design.The rest of the paper is structured as follows. In In the research of prestressed steel-concrete composite beams, Lou and Karavasilis evaluated the flexural performance of two-span prestressed steel-concrete composite beams and quantified the secondary bending moment. The nonlinear behavior of prestressed composite beam is simulated and verified by a continuous test . Chen coNeural network has strong parallelism and adaptability and can be applied to control, information, prediction, and so on. Chaudhary et al. proposed a method to predict the inelastic moment of continuous composite beams from elastic moment using neural network. The proposed neural network model predicts the inelastic moment ratio at the span support . Kumar eIn view of this, aiming at the flexural performance of prestressed steel-concrete continuous composite beams, a three-dimensional finite element numerical analysis model is established, and the whole test process is simulated based on BP neural network. At the same time, using this model, the mechanical deformation performance of prestressed steel-concrete continuous composite beam is further analyzed, and the effects of some parameters on the flexural performance of prestressed steel-concrete continuous composite beam are discussed, which provides a reference basis for engineering design.In this paper, four specimens are selected as the research objects. The specimens are four-point bending prestressed steel-concrete continuous composite beams with studs as complete shear connectors. The structure and basic parameters of the test piece are shown in Figures 2 and the ultimate stress is 1860 MPa.There are two types of reinforcement in concrete slab: HRB335 reinforcement with a diameter of 12 mm and a yield strength of 368mpa; HPB235 grade reinforcement has a diameter of 6 mm and has been cold drawn, with a yield strength of 372 MPa. The spacing between the stud ends of the other members is 361.80 mm, and the ultimate strength of the stud within the shear stud section is 361.80 mm. The area of single prestressed reinforcement is 139 mmZ direction. The combin39 element is set to translate along the Z axis and couple the degrees of freedom in the X and Y directions. Therefore, each node can slip and deform along the Z axis under the constraint of the bolt. The displacement constraints in X, Y, and Z directions are imposed on the joint at the support in the composite beam. At the joint at the end support of the composite beam, the displacement constraints in X and Y directions are applied. The external load is equivalent to the node load and applied at the corresponding position in the composite beam span.According to the test process, this paper establishes the ANSYS three-dimensional finite element numerical analysis model of prestressed steel-concrete continuous composite beam, as shown in 5 MPa. Poisson's ratio is 0.3, and the yield strength is selected according to the measured value.The ideal elastoplastic model (BISO) and von Mises yield criterion are adopted for steel beams, reinforcement, and concrete. The elastic modulus is 2 × 10ft is 0.26fcu2/3.Concrete is defined by the nonlinear elastic material model (MISO), and the failure criterion is Willam–Warnke five-parameter failure criterion. In the characteristic parameter table of concrete element, the crack opening shear transfer coefficient is 0.5 and the crack closing shear transfer coefficient is 0.95 . The conE0=1.95 × 105, f0.2=0.85fb, and fb is the ultimate stress of prestressed reinforcement. The initial yield point of prestressed reinforcement is taken as the proportional limit (fe=0.75fb).The uniaxial stress-strain relationship of prestressed reinforcement is calculated byV is shear force, s is slip, m = 0.558, n = 1 mm−1, and Vu is the ultimate bearing capacity of a single stud, which can be calculated by [fu is the ultimate tensile strength of the stud, Aus is the cross-sectional area of the stud, and Ec is the elastic modulus of the concrete. fc=0.76fu.The shear slip curve of the stud shows obvious nonlinear characteristics. This paper adopts the stud model proposed in the literature , 21:(2)Vlated by (3)Vu=0.4On the basis of considering the cracking and crushing of concrete, the plastic deformation of steel beam and the slip effect between concrete and steel beam, the Newton Raphson equilibrium iterative method, is adopted in this paper. In this method, the load substep is set to 400 steps, and the force load and displacement convergence criteria are adopted.The BP algorithm of back error propagation is called BP algorithm , 24. ItsP training samples in total, and the network trains the Nth sample pair. The input value is xi, the hidden value is yj, and the output value is Ok. The weights and thresholds between the hidden layer and the input layer are wji and θj, respectively. The weights and thresholds between the output layer and the hidden layer are wkj and θk, respectively. The expected value of the output layer is tk. For the Nth sample, the error value between the network output value Ok and the expected value tk is represented by E.Suppose there are The output of the hidden node is expressed asThe calculated output of the output node is expressed asThe error formula of the output node is expressed asSelect the number of hidden layers and their neurons and establish a neural network model.The error function used in training and the conditions for determining termination are given.Input training samples to train the network in step (1).Compare the output value with the real value and adjust the weight and threshold.Bring the results obtained in step (4) into the calculation. If the conditions given in step (2) are met, use the test data group and verification data group for verification. If not, repeat steps (2)–(4) or change the network model.Finally, the trained network is output.The BP neural network design training calculation process is mainly composed of the following steps:P − Δ), as shown in P is the load value and Δ is the midspan deflection value. It can be seen from the figure that the development trend of the curve obtained by finite element calculation is roughly the same as that of the test curve, which is in good agreement.Based on the neural network algorithm described in the previous section, we use the three-dimensional finite element numerical analysis model established in this paper to carry out nonlinear numerical simulation of the whole test process and calculate the load midspan deflection curve . The loading can be carried out only after the prestressed reinforcement is tensioned to the control value and the anchorage is completed until the composite beam is damaged.P − Δ basically develops in a linear relationship. At this stage, the prestressed continuous composite beam is in the elastic stage and has good working performance. At this stage, the nonlinear finite element calculation curve of prestressed steel-concrete continuous composite beam fits well with the test curve. Comparing the two specimens, it can be seen that the yield load of prestressed composite beam is about 0.87 Pu, which is greater than the end point of elastic section of ordinary steel composite beam by 0.65 Pu.Elastic working stage: at the initial stage of loading, the midspan curve P − Δ presents a typical nonlinear law. At this time, prestressed steel-concrete continuous composite beam has entered the elastic-plastic working stage.Elastoplastic working stage: with the continuous increase of load, the deflection growth rate of prestressed steel-concrete continuous composite beam is accelerating, and the curve Failure stage: when the load is close to the ultimate load, the prestressed continuous composite beam shows that the tension of the midspan section of the steel beam reaches the yield stage, while the compression of the midspan concrete slab reaches the ultimate load and the concrete is crushed. Plastic hinges appear in many places of prestressed continuous composite beams, resulting in a sharp decline in the bearing capacity of composite beams. At this time, the composite beam is in the plastic working stage.Taking PCCB3 specimen as an example, this paper explains the stress mechanism of prestressed steel-concrete continuous composite beam. Before the load is applied to the composite beam, the prestressed tensioning is carried out first, and the reverse arch appears in the middle of the span during the tensioning process. Prestressed steel-concrete continuous composite beam is a kind of statically indeterminate structure. Its midspan internal force and support reaction are determined by the stiffness distribution of the composite beam. When the bending moment in the negative bending moment area of the middle support exceeds the pressure dissipation bending moment established in advance before loading, the concrete on the upper part of the middle support cracks, the stiffness decreases, and the internal force redistributes. The nonlinear finite element method can accurately simulate the whole stress process of composite beam, which is mainly divided into the following four stages:P ≤ 0.6 pu), elastic-plastic deformation stage, and plastic deformation stage. The maximum slip value caused by prestressed inverted arch occurs at the sliding support, and the maximum value is −0.76 mm. The maximum slip value in the elastic stress stage is 0.97 mm, the maximum slip value in the elastic-plastic stress stage is 1.64 mm, and the maximum slip value in the plastic stress stage is 5.09 mm. The development range of slip value in plastic stress stage accounts for 67.78% of the total slip value.Taking PCCB3 beam as the reference beam, this paper discusses the effects of steel beam strength grade, concrete strength grade, web thickness, concrete slab thickness, and longitudinal and transverse reinforcement ratio on the flexural performance of prestressed steel-concrete continuous composite beam, as shown in The strength grade of steel beam has obvious influence on the flexural capacity of prestressed steel-concrete continuous composite beam, as shown in With the increase of concrete strength grade, the flexural capacity of composite beam has been improved to a certain extent, but the increase range is slow. When the concrete strength is increased from C30 to C40, the flexural capacity of composite beam is improved relatively greatly, and when the concrete grade is increased from C40 to C70, the bearing capacity is improved slightly. At the same time, the increase of concrete strength has little effect on the stiffness of composite beam in elastic working stage. In addition, the ductility of composite beam also increases with the increase of concrete strength grade, as shown in With the increase of the web thickness of the steel beam, the flexural capacity and stiffness of the composite beam increase, especially for the stiffness in the elastic working stage, as shown in With the increase of concrete slab thickness, the flexural capacity and stiffness of composite beams increase. The influence mechanism is to increase the height of the compression zone of the concrete slab to improve the flexural capacity of the composite beam, as shown in Increasing the transverse reinforcement ratio of concrete slab can improve the flexural capacity of composite beams to a certain extent, but the effect is not obvious. With the increase of transverse reinforcement ratio of concrete slab, the ductility of specimens is continuously improved. It shows that the increase of stirrup reinforcement ratio can not only restrict the deformation of concrete but also better promote the cooperative work of concrete and steel beam, as shown in When using different loading methods in the calculation of composite beams, it can be seen that the effect of composite beams on different loading methods is very different. Through the comparison of the two curves in High-strength steel is used in composite beams, which has high flexural capacity and superior plastic deformation capacity.Increasing the concrete strength grade can increase the flexural capacity and ductility of composite beams, but the influence degree decreases with the further increase of concrete strength. Considering certain economic performance, this paper suggests to select C30 ∼ C50 strength concrete in engineering design.Increasing the thickness of concrete slab and steel beam web can effectively improve the flexural capacity of composite beams. Among them, the increase of web thickness of steel beam is more obvious to improve the stiffness of composite beam in the elastic working stage.Increasing the transverse reinforcement ratio can improve the ultimate bearing capacity of composite beams. The increase of stirrup reinforcement ratio can not only restrict the deformation of concrete but also better promote the cooperative work of concrete and steel beam.Under different loading modes, the action effects of composite beams are obviously different. When designing the composite beam, it is based on the actual stress characteristics of the composite beam.In this paper, aiming at the mechanical performance of prestressed steel-concrete continuous composite beam, the whole process is simulated by numerical analysis method, and the failure mechanism, bearing capacity, and main influencing factors of prestressed steel-concrete continuous composite beam are analyzed. The main results are summarized as follows:At present, the mechanical performance, dynamic performance, fatigue performance, construction performance, and seismic performance of prestressed rigid concrete continuous composite beams under long-term effect are rarely involved in the current research. The research team will carry out the above related experimental research in the next step.


Concrete structures perform poorly when withstanding thermal shock events, usually requiring repair or replacement after one single instance. In certain industries , these events are not only likely but frequent, which represents a considerable financial burden. One option to solve this issue would be to decrease the heating rate imposed onto the concrete material through the use of a protective surface layer. In this work, the suitability of dunite and microgabbro as protective materials is explored through X-ray diffraction, thermal dilation, optical microscopy, X-ray microtomography, thermo-gravimetric analysis and a compressive test. Further, the thermal dilation was used as an input to simulate a composite concrete-rock wall and the respective stresses caused by a thermal shock event. The dehydration of chrysotile in dunite and the decomposition of analcime, chamosite and pumpellyite in microgabbro were both favourable for the performance of the stones in the desired application. The thermal stability and deformation were found in the range of what can be applied directly on concrete; however, it was clear that pre-heating treatment results in a far more durable system in a cyclic thermal load situation. Concrete structures are weak against thermal shock events ,2,3, neeT≥300 °C . HoweverWhile not a major point of concern in the design of residential buildings, facilities for specific industries suffer from frequent thermal shock events and the accompanying need for repairs. Further, the constant replacement of a structure is time consuming and not environmentally sustainable. Yet, concrete is still the most used option for such structures given its low cost, relatively low specific weight and its ability to be cast into most desired geometries.C is a constant, E is the Young’s modulus, V is the volume and The response of solid materials to thermal shock can be theoretically described by Equation  8] in w in w8] ial shock ,10.(1)ΔWhile the second term of the equation is governed by project specific requirements, the first term is largely dependent on the material design. Therefore, a high-performance mix can be selected to delay cracking at high temperatures. Yet, high-performance concrete behaves notoriously worse than ordinary concrete during thermal shock events ,11,12. TInstead, the thermo-hydral damage mechanism can cause explosive detachment when the water vapour inside the pores of the material cannot readily escape ,14,15. TA different approach would be to decrease the heating rate instead of changing the material properties. It was found that at fast heating rates, such as the ones in fire events, spalling occurs due to temperature-gradient-induced stresses, resulting in violent events . HoweverThe problem lies in how to achieve the necessary decrease in the heating rate. Factories and industrial facilities rarely have the possibility of changing the operation temperature of their products; thus, a different solution must be sought. A protective surface layer better suited to withstand high-temperature spills could be added to the concrete structure. Such an overlay element would heat up and dissipate energy before the underlaying concrete can be affected and later slowly transfer the warmth to the substrate structure, greatly decreasing the danger of explosive spalling.However, a number of conditions must be met before choosing a material for such an application. Because of the size of structures usually encountered in such facilities, the material would have to be available in large quantities and within reasonable geographical proximity. Furthermore, it would be desirable for it to possess a similar thermal dilation to concrete at low temperatures while displaying lower strains at high temperatures. It should also be chemically stable at high temperatures to allow for good durability when exposed to frequent events and possess high toughness to resist eventual impacts. Finally, a compressive strength similar or superior to the used concrete would be desirable.This paper studies the viability of dunite and microgabbro as protective surface layers in concrete structures in order to protect them against high-temperature thermal shock events. The main research question pertains to the engineering properties of such rocks in their natural state and after being exposed to high temperatures and whether these would eventually be compatible with conventional concrete mixes.These two rocks were pre-selected based on their geological properties and availability, as a starting point. Later, in order to investigate the mechanical and chemical properties, samples were prepared for thermogravimetric analysis, X-ray diffraction, thermal dilation, optical microscopy and X-ray microtomography. By looking at the chemical shift on the rocks after their heating and their respective microstructural response, conclusions were drawn regarding their adequacy for the task. Further, the thermal dilation was used as an input to simulate a composite concrete-rock wall and study the respective stresses caused by a thermal shock event.Dunite was mined from the Orhaneli ophiolite, situated in the western part of the Izmir–Ankara–Erzincan Suture Zone and south of Bursa (Turkey), an area that exposes cumulates belonging to the mantle–crust transition zone . MicrogaIn order to determine the mineralogical composition of the rocks, samples  were ground to fine powder and kept dry until testing through X-ray diffraction. A Bruker D8 Advance diffractometer Bragg–Brentano geometry and Lynxeye position sensitive detector was used with . (2022) .Powder samples, prepared in the same fashion as described in . (2017) .To complement the results of X-ray diffraction while simulating a thermal shock event, optical microscopy was performed. For this test, plates of 80 mm of length and width with 30 mm of depth were cut. Each plate then was exposed to 40 g of molten slag heated at 1530 s (2016) .The analysis was performed through a Leica DM2500P optical microscope equipped with linear and circular polarisation filters. Lenses of magnification and numerical aperture equivalent to 2.5/0.07, 10/0.22 and 20/0.4, respectively, were available. Plain polarised light (PPL) and cross polarised light (XPL) were used. The camera used to acquire the micrographs was a Leica DFC310FX digital camera, with a 1392 × 1040 resolution. Proprietary software was used for the image acquisition.For the quantification of different components of the rocks, cylindrical samples of non-heated dunite and microgabbro were scanned by a Phoenix Nanotom X-ray CT scanner. These samples were then heated to a temperature of 900 . (2020) .Bruker’s DataViewer software was used for registration. The scanners of the natural stones could be registered to their pre-heated counterpart through true 3D registration using rigid transform, so expansion could also be detected. The post-processing of the images was performed using the freeware Fiji image analysis .For dunite scans, a Gaussian blur filter (with 2 pixel radius) was used, followed by a non-local means denoising filter  in orderCylindrical cores were extracted from non-heated dunite, pre-heated dunite, non-heated microgabbro and pre-heated microgabbro. The dimensions of these were 5 mm in diameter and varying heights between 3 mm and 7 mm. A Perkin Elmer TMA 4000 thermomechanical analyser was used to determine the coefficient of thermal expansion (CTE) of the samples. The CTE was determined by heating each sample from ambient temperature (24 Three cubes with 40 mm sides were tested for each rock in order to determine compressive strength according to NEN-EN 1926:2007 . Samples® 5.3) was used to simulate the behaviour of a composite wall with a concrete substrate and a stone overlay exposed to hot spills. This analysis is performed to gain insight into the suitability of the pre-selected material as concrete overlay. The simulated concrete wall had 3 m in height, 10 m in length and 50 cm in depth. The stone element was created with equal height and length, but only 10 cm deep. A spill in one quarter of the wall was designed to create a sudden thermal shock from ambient temperature up to 1000 A finite element software  , also inous SiO2 .The results for the thermogravimetric analyses are presented in rysolite . On the analcime , althoug°C range . The sechamosite . Pumpelld 300 °C ; thus, iThe microgabbro displays a typical subhedral aspect with a phaneritic texture in Through the registration process, it was clear that, after cooling, the heated samples return to their natural size, demonstrating good dimensional stability. The tomography of the dunite reveals three phases in , as expeAccording to Equation , the chr3  and the The serpentine conversion can be further inferred by the better contrast in the scan after heating (caused by the greater difference in the density of the phases) and by the 20% decrease in dark grey phases followed by the same proportional increase in the bright grey phases. This is a volume indication of how much forsterite and silica were generated from the change in the chrysotile. In accordance with the other tests, the zincochromite was not affected by the heating of the sample, remaining at approximately 0.7% in volume. The summary of the segmentation results can be found in Besides the total sample volume change, individual grains were investigated regarding their shift in surface area and volume. This is because the complex shape of the phases renders most geometrical measurements  useless. Hence, only 3D information, such as the two measurements cited, could be reliably compared. As the zincochromite remained mostly unchanged after heating, the changes for the chrysotile are displayed in The tomography of the microgabbro only reveals three distinguishable phases see . BecauseThe analcime was indistinguishable from the albite; thus, it could not be analysed. The augite was not affected by the heating treatment. However, the changes in the pumpellyite and chamosite display a far larger shift in volume than in surface area see . As expeThe results for the compressive strength are displayed in Besides the increase in expansion, the difference between the expansions of non-heated and pre-heated dunite were almost linear, only diminishing at temperatures higher than 700 Due to the stones capacity for energy absorption and the amount of molten material simulated, the temperature in the concrete wall layer can be kept below 100 In the dunite samples, the conversion of the chrysotile to forsterite and silica, as theorised in Equation  and indiRegarding the thermal dilation, both non-heated and pre-heated dunite show similar behaviour at a low temperature. After 100 The small decrease in the microgabbro ultimate compressive strength was likely due to the small increase in porosity in its microstructure introduced by the conversion of pumpellyite, chamosite and analcime into magnesium oxide and Although the observations through optical microscopy and microtomography both displayed limited changes in the microstructure, the change in the samples’ expansion caused by thermal loading was considerable. Unlike the dunite samples, the microgabbro samples presented a complex behaviour in which the difference between the natural and the pre-heated samples starts as early as 50 In line with the results of the DTG and the findings of Caillére and Hénin , the steterlayer .It seems clear that chamosite plays a dominant role in the thermal expansion behaviour of the studied microgabbro samples. As its full decomposition is not finished until temperatures are slightly above 800 °C , the perAs the stresses in the concrete shown in  were derThe present study proposed dunite and microgabbro as possible building materials to be used as a protective surface layer to concrete structures that are repeatedly exposed to high temperatures in industrial environments or otherwise. The main function of such surface layers would be to endure the thermal shock present in such environments and transfer the heat to the concrete at a much slower rate, reducing the risk of concrete spalling. To achieve this goal, the microstructure, mechanical properties and the thermal performance of these minerals have been studied.The main changes in dunite were caused by the dehydration of chrysotile, which provides improvements in both mechanical and thermal properties. The structural changes in microgabbro were more complex, involving the decomposition of analcime, pumpellyite and chamosite, the latter only becoming complete after 800 The authors found that both rocks present befitting properties to their use as a protection layer in industrial applications. However, it is clear that pre-heating results in a far more durable system in a cyclic thermal load situation. Furthermore, the increase in strength in dunite was previously missing in the literature and requires further investigation.


Significant reductions in microbial diversity were observed following minocycline and doxycycline exposure, which failed to recover post antibiotic withdrawal. Specifically, minocycline caused a ~10% decline in Lactobacillaceae and Bifidobacteriaceae abundances, while doxycycline caused a ~7% decline in Lactobacillaceae and Bacteroidaceae abundances. Both minocycline and doxycycline were associated with a large expansion (>10%) of Enterobacteriaceae. Sarecycline caused a slight decline in bacterial diversity at the start of treatment, but abundances of most families remained stable during treatment. Ruminococcaceae and Desulfovibrionaceae decreased 9% and 4%, respectively, and a transient increased in Enterobacteriaceae abundance was observed during sarecycline administration. All populations recovered to pre-antibiotic levels after sarecycline exposure. Overall, sarecycline had minimal and transient impact on the gut microbiota composition and diversity, when compared to minocycline and doxycycline.Treatment for moderate-to-severe acne vulgaris relies on prolonged use of oral tetracycline-class antibiotics; however, these broad-spectrum antibiotics are often associated with off-target effects and negative gastrointestinal sequelae. Sarecycline is a narrow-spectrum antibiotic treatment option. Here, we investigated the effect of prolonged sarecycline exposure, compared with broad-spectrum tetracyclines (doxycycline and minocycline) upon the colonic microbiota. Three  Acne vulgaris (acne) is a chronic disease characterized by inflammatory lesions of the skin with different degrees of severity. Acne has been reported as one of the 10 most common diseases globally , with EuCutibacterium acnes (formerly Propionibacterium acnes), and also aerobic Gram-positive cocci, such as Staphylococcus aureus (including MRSA), but has reduced in vitro activity against other aerobic and anaerobic bacteria, such as Klebsiella pneumoniae, Escherichia coli, Bifidobacterium bifidum, and Lactobacillus acidophilus  as previously described  made from fecal donations from five healthy adults with no history of antibiotic use in the previous 3 months.A total of three gut models were set as described above and run in these experiments. For each model, the microbial populations were allowed to stabilize for 2 weeks until reaching a “steady state.” Each model received a different antibiotic at a concentration reflective of the reported antibiotic colonic values in humans. Antibiotics were instilled as follows: Model S was dosed with sarecycline , model M was dosed with minocycline . A bacterial population was considered to be significantly impacted when the log2 −2 ≤ fold change ≥2 in comparison with baseline enumerated levels.Bacterial populations were sampled daily in each of the three models, in which a 10-fold dilution series of this sample was plated out onto various selective and non-selective agars for enumeration as described previously . BacteriKocuria rhizophila (ATCC 9341) was inoculated into Wilkins-Chalgren agar plates. A calibration series of the antibiotic was added to each plate alongside the samples. Zone diameters were measured, and concentration curves plotted so that unknown concentrations from vessel supernatants could be determined. Assays were performed in triplicate. Concentrations of doxycycline were determined as described above but using S. aureus (ATCC 29213) as indicator microorganism and iso-sensitest agar as growth media.The concentration of each antibiotic was determined by bioassays as previously described . BrieflyTM Spin Kit for Soil , following manufacturer’s instructions. Extracts were stored at −80°C.All three models were sampled for bacterial 16S testing at key timepoints. Sampling regimen is shown in Bacterial 16S rRNA V4 region libraries were prepared as previously detailed . SequencDemultiplexed FASTQ files of 16S sequences were trimmed of adapter sequences using CLC Genomics Workbench (version 20.0.4). The paired reads were joined together and assembled into the contigs, and quality controlled based on the parameters such as maxambig = 0, minlength = 150 and maxlength = 500 (default settings). Unique sequences were aligned against the SILVA reference database (v132 97%). OTUs  were identified by clustering the sequences and were assigned the consensus taxonomy information with label = 0.03. For the diversity measurements, Shannon diversity index was computed for all samples and the distance matrix based on 0.5 UniFrac distance was used for principal coordinates (PCoA) analysis and visualization for each group of samples.Datasets related to this article can be found hosted at Sequence Read Archive under BioProject ID: PRJNA744500.in vitro gut models, primed with a pooled fecal slurry, were left untreated to allow the microbial populations to equilibrate  in the gut model; however, the level of sarecycline was undetectable 3 days after cessation of dosing. After the first week of antibiotic dosing, the microbial patterns showed an initial minor decline in the Shannon diversity index, an indicator of sample diversity ,B. HowevAdministration of minocycline, once daily for 3 weeks, achieved a mean bioactive concentration of 27.4 mg/L  in the gut model. This caused profound changes to the bacterial populations; the microbial populations markedly shifted from pre-minocycline levels, and we observed a major decline in the microbial diversity ,B. The rFollowing a once daily dosing of doxycycline for 3 weeks, we detected a mean bioactive concentration of 23.8 mg/L  in the model. This dosing regimen of doxycycline resulted in continuous shifts in the microbiota with an increasing variation from pre-antibiotic levels and reduced microbial diversity ,B. DoxycTo explore the effects of each antibiotic on the microbiota across each independent gut model, a heat map was constructed, with clustering based on Euclidean distance, showing the changes in the relative abundances of the bacterial families over time . Prior tLactobacillus, Enterobacteriaceae, and Bacteroides species (Enterococcus species by the end of sarecycline therapy (p ≤ 0.05); however, this population returned to pre-sarecycline levels during the recovery phase. In contrast, minocycline caused a 6.1-fold reduction in the Lactobacillus spp., and a 5- and 4.1-fold increase in Enterobacteriaceae and Enterococcus spp., respectively  reductions to the Lactobacillus (−4.2-fold) and Bacteroides (−3.6-fold) populations and increased levels of Enterococcus spp. .Direct enumeration of the key gut microbial populations after antibiotic therapy and during the recovery phase, compared with pre-antibiotic levels, showed that sarecycline had the lowest propensity to cause dysbiosis, with no significant change to the  species . Sarecycectively ; howeverBacteroides population upon exposure, there was a change in the dominant Bacteroides species after exposure to all antibiotics  can be found at: The collection and use of human fecal samples from healthy adult volunteers was performed under informed consent and was approved by the Leeds Institute of Health Sciences and Leeds Institute of Genetics, Health and Therapeutics and Leeds Institute of Molecular Medicine, University of Leeds Joint Ethics Committee .IM, AB, and MW designed and overviewed the experimental studies. AB, IM, WS, EC, DE, and JA conducted the experiments. IM and AB analyzed the experimental data and wrote the manuscript with additional input from MW, AG, and EF. All authors contributed to the article and approved the submitted version.This study was financially supported by the Almirall S.A. The funder had no involvement in experiment design and data analysis but has approved the final manuscript.IM has received funding to attend conferences from Techlab, Inc. AG is the Head of R&D at Almirall (United States). EF formerly Almirall Global Medical Affairs (currently with Moderna). MW has received honoraria for consultancy work, financial support to attend meetings and research funding from Astellas, AstraZeneca, Abbott, Actelion, Alere, Bayer, bioMérieux, Cerexa, Cubist, Da Volterra, Durata, Merck, Nabriva Therapeutics plc, Pfizer, Qiagen, Roche, Seres Therapeutics Inc., Synthetic Biologics, Summit, and The Medicines Company. AB has received financial support to attend meetings and research funding from Seres Therapeutics Inc., Motif Biosciences plc., Nabriva Therapeutics plc, Tetraphase Pharmaceuticals, Almirall SA, GlaxoSmithKline plc, and Hayashibara Co. Ltd.The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.