BACKGROUND:Obesity is not only related to metabolic diseases such as diabetes and cardiovascular disease,but also closely related to the increased risk of cognitive decline,dementia and other neurodegenerative diseases.Studies have found that aerobic exercise and resistance exercise can help improve obesity-related cognitive impairment,but their therapeutic effects and related mechanisms of action are still unclear.OBJECTIVE:To explore the protective effects of aerobic and resistance exercises on the nervous center of obesity-related cognitive impairment mice.METHODS:Forty-eight 8-week-old C57BL/6J wild-type male mice were randomly divided into four groups:a control group was fed normally for 20 weeks;a high fat group was fed with high fat diet(60％fat energy)for 20 weeks;an aerobic exercise group was fed with 12 weeks of high-fat diet followed by 8 weeks of aerobic exercise;and a resistance exercise group was fed with 12 weeks of high-fat diet followed by 8 weeks of resistance exercise.After the exercise intervention,body mass was weighed,insulin tolerance and glucose tolerance were tested to evaluate insulin resistance,and cognitive function of mice in each group was detected by new object recognition experiment and Y-maze experiment.The morphology of hippocampal and cortical tissue cells was observed by hematoxylin-eosin staining.The mRNA relative expression levels of tumor necrosis factor-α and interleukin-6 were detected by real-time fluorescence quantitative PCR,and the protein expressions of Bax,Bcl-2,nuclear factor-κB,Cleaved Caspase-1,Caspase-3,synapsin 1 and brain-derived neurotrophic factor were detected by western blot.RESULTS AND CONCLUSION:(1)Compared with the control group,the body mass of mice increased in the high-fat group(P＜0.05),accompanied by insulin resistance and cognitive dysfunction,the expression levels of nuclear factor-κB,Bax,Caspase-3,Cleaved Caspase-1 in the hippocampus were significantly increased(P＜0.05),the expression levels of brain-derived neurotrophic factor,synapsin 1and Bcl-2 proteins were significantly decreased(P＜0.05),Bcl-2/Bax ratio was significantly decreased(P＜0.05),and the mRNA levels of inflammatory cytokines,tumor necrosis factor-α and interleukin-6,were significantly up-regulated(P＜0.05).(2)Compared with the high-fat group,the above indexes were significantly improved in the aerobic exercise group(P＜0.05),while in the resistance exercise group,the body mass of mice was significantly decreased,the levels of inflammatory cytokines tumor necrosis factor-α and interleukin-6 mRNA were significantly decreased(P＜0.05),the protein expression of Caspase-3 was significantly decreased(P＜0.05),and the protein expression of brain-derived neurotrophic factor was significantly up-regulated(P＜0.05),but no significant changes were observed in the other indexes(P＞0.05).In conclusion,long-term exercise can reduce insulin resistance,down-regulate the expression of nuclear factor-κB pathway,weaken inflammatory response,inhibit neuronal apoptosis and improve synaptic plasticity,resulting in neuroprotective effects,and effectively alleviate obesity-related cognitive dysfunction in obese mice.The therapeutic effect of aerobic exercise is superior to that of resistance exercise.

BACKGROUND:Obesity is not only related to metabolic diseases such as diabetes and cardiovascular disease,but also closely related to the increased risk of cognitive decline,dementia and other neurodegenerative diseases.Studies have found that aerobic exercise and resistance exercise can help improve obesity-related cognitive impairment,but their therapeutic effects and related mechanisms of action are still unclear.OBJECTIVE:To explore the protective effects of aerobic and resistance exercises on the nervous center of obesity-related cognitive impairment mice.METHODS:Forty-eight 8-week-old C57BL/6J wild-type male mice were randomly divided into four groups:a control group was fed normally for 20 weeks;a high fat group was fed with high fat diet(60％fat energy)for 20 weeks;an aerobic exercise group was fed with 12 weeks of high-fat diet followed by 8 weeks of aerobic exercise;and a resistance exercise group was fed with 12 weeks of high-fat diet followed by 8 weeks of resistance exercise.After the exercise intervention,body mass was weighed,insulin tolerance and glucose tolerance were tested to evaluate insulin resistance,and cognitive function of mice in each group was detected by new object recognition experiment and Y-maze experiment.The morphology of hippocampal and cortical tissue cells was observed by hematoxylin-eosin staining.The mRNA relative expression levels of tumor necrosis factor-α and interleukin-6 were detected by real-time fluorescence quantitative PCR,and the protein expressions of Bax,Bcl-2,nuclear factor-κB,Cleaved Caspase-1,Caspase-3,synapsin 1 and brain-derived neurotrophic factor were detected by western blot.RESULTS AND CONCLUSION:(1)Compared with the control group,the body mass of mice increased in the high-fat group(P＜0.05),accompanied by insulin resistance and cognitive dysfunction,the expression levels of nuclear factor-κB,Bax,Caspase-3,Cleaved Caspase-1 in the hippocampus were significantly increased(P＜0.05),the expression levels of brain-derived neurotrophic factor,synapsin 1and Bcl-2 proteins were significantly decreased(P＜0.05),Bcl-2/Bax ratio was significantly decreased(P＜0.05),and the mRNA levels of inflammatory cytokines,tumor necrosis factor-α and interleukin-6,were significantly up-regulated(P＜0.05).(2)Compared with the high-fat group,the above indexes were significantly improved in the aerobic exercise group(P＜0.05),while in the resistance exercise group,the body mass of mice was significantly decreased,the levels of inflammatory cytokines tumor necrosis factor-α and interleukin-6 mRNA were significantly decreased(P＜0.05),the protein expression of Caspase-3 was significantly decreased(P＜0.05),and the protein expression of brain-derived neurotrophic factor was significantly up-regulated(P＜0.05),but no significant changes were observed in the other indexes(P＞0.05).In conclusion,long-term exercise can reduce insulin resistance,down-regulate the expression of nuclear factor-κB pathway,weaken inflammatory response,inhibit neuronal apoptosis and improve synaptic plasticity,resulting in neuroprotective effects,and effectively alleviate obesity-related cognitive dysfunction in obese mice.The therapeutic effect of aerobic exercise is superior to that of resistance exercise.

Background: High-mobility group box protein 1 (HMGB1) is a chromatin-binding protein involved in arthritis, ischemia, sepsis, atherosclerosis, neurodegenerative disorders, meningitis, and cancer. HMGB1 exhibits dual roles in cancer, acting as either a tumor suppressor or oncoprotein depending on context. Objective: This research aimed to elucidate HMGB1’s functional significance in cutaneous squamous cell carcinoma (cSCC). Methods: We overexpressed HMGB1 in cSCC cell lines using recombinant adenovirus and examined its effects on cell proliferation, colony formation, and cell migration. Results: Immunohistochemical analysis revealed elevated HMGB1 expression levels in cSCC tissue relative to normal epidermis. To assess the influence of HMGB1, we employed recombinant adenoviruses expressing HMGB1 to transduce SCC cell lines (SCC12 and SCC13). Enhanced HMGB1 expression significantly promoted cellular proliferation and colony formation capacity.Notably, HMGB1 overexpression elevated the levels of proliferation regulators, including P63, SOX2, CDK4 and CDK6. Furthermore, HMGB1 overexpression substantially enhanced tumor invasiveness, accompanied by upregulation of epithelial-mesenchymal transition (EMT) biomarkers. Mechanistically, overexpression of HMGB1 enhanced transforming growth factor-β signaling by increasing phosphorylation of SMAD2/3, the key mediators of EMT. Conclusion These data imply that HMGB1 acts as a tumor-promoting factor in cSCC.

ObjectiveTo investigate the potential mechanism of heat-sensitive moxibustion on chronic atrophic gastritis （CAG） through the phosphoinositide 3-kinase/protein kinase B （PI3K/Akt） signaling pathway. MethodsFifty-eight SD rats were randomly divided into blank group （n=14） and modeling group （n=44）. Rats in the blank group were fed routinely， while the rats in the modeling group received drinking water containing 1-methyl-3-nitro-1-nitrosoguanidine （MNNG） at a concentration of 140 μg/ml， combined with irregular fasting and feeding for 12 weeks to establish CAG model. After successful modeling， the rats were randomly divided into model group （n=10）， inhibitor group （n=10） and moxibustion group （n=20）. After 40 minutes of suspended moxibustion at "Zhongwan" （CV 12） daily， the rats in the moxibustion group were divided into heat-sensitive moxibustion group （n=10） and non-heat-sensitive moxibustion group （n=9） according to the change of tail temperature during moxibustion. The inhibitor group was bound for 40 minutes daily， and then administered with PI3K/Akt signaling pathway inhibitor， rapamycin solution， by gavage at a dose of 1 mg/kg. The model group received intragastric administration of 1 ml/kg normal saline after 40 minutes of restraint stress each day. All interventions were administered once daily for 28 consecutive days， while the blank group received no intervention. After the intervention finished， the body weight of rats in each group was compared. HE staining was used to observe the histopathological changes of gastric mucosa. The apoptosis-positive rate of gastric mucosal cells was detected by TUNEL assay. Immunohistochemistry was performed to determine the protein levels of matric metalloproteinase-7 （MMP7）， vascular endothelial growth factor A （VEGFA） and epidermal growth factor receptor （EGFR） in gastric mucosa. The mRNA expression levels of PI3K， Akt and mammalian target of rapamycin （mTOR） in gastric mucosal tissues were detected by qPCR. The protein levels of phosphorylated Akt （p-Akt） and phosphorylated mTOR （p-mTOR） in rat gastric mucosal tissues were measured by Western Blotting. ResultsCompared to the blank group， rats in all other groups exhibited decreased body weight， significantly increased gastric mucosal cell apoptosis-positive rates， elevated protein levels of MMP7， VEGFA and EGFR in gastric mucosa， increased mRNA expression levels of PI3K， Akt and mTOR， and enhanced protein expression levels of p-Akt and p-mTOR （P＜0.05 or P＜0.01）. Histopathological examination revealed thinning of the gastric mucosa， glandular disorganization and atrophy， accompanied by intestinal metaplasia.Compared to the model group， the heat-sensitive moxibustion group， the non-heat-sensitive moxibustion group and the inhibitor group all showed significant improvements in the above-mentioned indicators （P＜0.05 or P＜0.01）. Compared to the heat-sensitive moxibustion group， the non-heat-sensitive moxibustion group and the inhibitor group exhibited increased positive rates of gastric mucosal cell apoptosis； the non-heat-sensitive moxibustion group showed increased protein levels of MMP7， VEGFA and EGFR， as well as mRNA expression levels of PI3K， Akt and mTOR， and protein expressions of p-Akt and p-mTOR； the inhibitor group exhibited elevated protein expression level of EGFR （P＜0.05 or P＜0.01）. Histopathological examination showed that the gastric mucosal glands in the heat-sensitive moxibustion group were arranged more regularly， with an approximately normal structural appearance. ConclusionHeat-sensitive moxibustion can improve the body weight of CAG rats and repair gastric mucosal injury. Its therapeutic effects may be mediated by inhibiting excessive activation of gastric mucosal PI3K/Akt signaling pathway， thereby reducing gastric mucosal cell apoptosis.

ObjectiveTo investigate the potential mechanism of heat-sensitive moxibustion on chronic atrophic gastritis （CAG） through the phosphoinositide 3-kinase/protein kinase B （PI3K/Akt） signaling pathway. MethodsFifty-eight SD rats were randomly divided into blank group （n=14） and modeling group （n=44）. Rats in the blank group were fed routinely， while the rats in the modeling group received drinking water containing 1-methyl-3-nitro-1-nitrosoguanidine （MNNG） at a concentration of 140 μg/ml， combined with irregular fasting and feeding for 12 weeks to establish CAG model. After successful modeling， the rats were randomly divided into model group （n=10）， inhibitor group （n=10） and moxibustion group （n=20）. After 40 minutes of suspended moxibustion at "Zhongwan" （CV 12） daily， the rats in the moxibustion group were divided into heat-sensitive moxibustion group （n=10） and non-heat-sensitive moxibustion group （n=9） according to the change of tail temperature during moxibustion. The inhibitor group was bound for 40 minutes daily， and then administered with PI3K/Akt signaling pathway inhibitor， rapamycin solution， by gavage at a dose of 1 mg/kg. The model group received intragastric administration of 1 ml/kg normal saline after 40 minutes of restraint stress each day. All interventions were administered once daily for 28 consecutive days， while the blank group received no intervention. After the intervention finished， the body weight of rats in each group was compared. HE staining was used to observe the histopathological changes of gastric mucosa. The apoptosis-positive rate of gastric mucosal cells was detected by TUNEL assay. Immunohistochemistry was performed to determine the protein levels of matric metalloproteinase-7 （MMP7）， vascular endothelial growth factor A （VEGFA） and epidermal growth factor receptor （EGFR） in gastric mucosa. The mRNA expression levels of PI3K， Akt and mammalian target of rapamycin （mTOR） in gastric mucosal tissues were detected by qPCR. The protein levels of phosphorylated Akt （p-Akt） and phosphorylated mTOR （p-mTOR） in rat gastric mucosal tissues were measured by Western Blotting. ResultsCompared to the blank group， rats in all other groups exhibited decreased body weight， significantly increased gastric mucosal cell apoptosis-positive rates， elevated protein levels of MMP7， VEGFA and EGFR in gastric mucosa， increased mRNA expression levels of PI3K， Akt and mTOR， and enhanced protein expression levels of p-Akt and p-mTOR （P＜0.05 or P＜0.01）. Histopathological examination revealed thinning of the gastric mucosa， glandular disorganization and atrophy， accompanied by intestinal metaplasia.Compared to the model group， the heat-sensitive moxibustion group， the non-heat-sensitive moxibustion group and the inhibitor group all showed significant improvements in the above-mentioned indicators （P＜0.05 or P＜0.01）. Compared to the heat-sensitive moxibustion group， the non-heat-sensitive moxibustion group and the inhibitor group exhibited increased positive rates of gastric mucosal cell apoptosis； the non-heat-sensitive moxibustion group showed increased protein levels of MMP7， VEGFA and EGFR， as well as mRNA expression levels of PI3K， Akt and mTOR， and protein expressions of p-Akt and p-mTOR； the inhibitor group exhibited elevated protein expression level of EGFR （P＜0.05 or P＜0.01）. Histopathological examination showed that the gastric mucosal glands in the heat-sensitive moxibustion group were arranged more regularly， with an approximately normal structural appearance. ConclusionHeat-sensitive moxibustion can improve the body weight of CAG rats and repair gastric mucosal injury. Its therapeutic effects may be mediated by inhibiting excessive activation of gastric mucosal PI3K/Akt signaling pathway， thereby reducing gastric mucosal cell apoptosis.

ObjectiveTo evaluate the clinical efficacy and safety of the Qishen Liuwei presoription for senile hypertension complicated with frailty （of Qi deficiency and blood stasis pattern， or deficiency of both spleen and kidney pattern）. MethodsA single-center， randomized controlled clinical trial design was employed in this study. Sixty-four eligible patients， treated at the Cardiology Outpatient Clinic of Dongfang Hospital， Beijing University of Chinese Medicine between June 2024 and February 2025， were randomly allocated into an observation group or a control group， with 32 patients in each group. Both groups received standard conventional antihypertensive therapy， while the observation group additionally received the Qishen Liuwei Formula （one dose per day， in separate servings in the morning and evening）. For both groups， a treatment course consisted of 4 weeks， followed by a 2-month follow-up period. Then， the primary indicator （Fried frailty phenotype scores）， along with secondary indicators including traditional Chinese medicine （TCM） syndrome scores and changes in blood pressure were observed before and after treatment. ResultsRegarding Fried frailty phenotype scores， the observation group exhibited significantly improved grip strength， 4.57 m walk time， the duration of weekly walks， ''effort required for any activity''， and ''inability to walk forward'' after treatment， while only the latter two indicators were significantly improved in the control group （P<0.05）. Compared with the control group， the observation group demonstrated significantly superior improvement in the duration of weekly walks， ''effort required for any activity''， and frailty （P<0.05）. For total TCM syndrome scores， both groups displayed significantly decreased total TCM syndrome scores （P<0.05） after treatment， and the decrease was more significant in the observation group （P<0.05）. Regarding office blood pressure， both groups showed significantly decreased diastolic blood pressure and mean arterial pressure after treatment， while the observation group also showed significantly decreased systolic blood pressure （P<0.05）. During treatment， one case of facial rash occurred in the observation group， representing an adverse reaction rate of 3.13% （1/32）. The rash resolved one week after discontinuation of medication. No adverse reactions occurred in the control group during treatment. No statistically significant difference was observed in the incidence of adverse reactions between the two groups. ConclusionFor senile hypertension complicated with frailty， the Qishen Liuwei presoription effectively improves physical activity， muscle strength， frailty-related symptoms， and TCM syndrome remission. When combined with Western medicine， the Formula contributes to stable blood pressure control and demonstrates a favorable clinical safety profile， indicating its clinical application potential.

Alzheimer’s disease (AD) is a central neurodegenerative disease characterized by progressive cognitive decline and memory impairment in clinical. Currently, there are no effective treatments for AD. In recent years, a variety of therapeutic approaches from different perspectives have been explored to treat AD. Although the drug therapies targeted at the clearance of amyloid β-protein (Aβ) had made a breakthrough in clinical trials, there were associated with adverse events. Neuroinflammation plays a crucial role in the onset and progression of AD. Continuous neuroinflammatory was considered to be the third major pathological feature of AD, which could promote the formation of extracellular amyloid plaques and intracellular neurofibrillary tangles. At the same time, these toxic substances could accelerate the development of neuroinflammation, form a vicious cycle, and exacerbate disease progression. Reducing neuroinflammation could break the feedback loop pattern between neuroinflammation, Aβ plaque deposition and Tau tangles, which might be an effective therapeutic strategy for treating AD. Traditional Chinese herbs such as Polygonum multiflorum and Curcuma were utilized in the treatment of AD due to their ability to mitigate neuroinflammation. Non-steroidal anti-inflammatory drugs such as ibuprofen and indomethacin had been shown to reduce the level of inflammasomes in the body, and taking these drugs was associated with a low incidence of AD. Biosynthetic nanomaterials loaded with oxytocin were demonstrated to have the capability to anti-inflammatory and penetrate the blood-brain barrier effectively, and they played an anti-inflammatory role via sustained-releasing oxytocin in the brain. Transplantation of mesenchymal stem cells could reduce neuroinflammation and inhibit the activation of microglia. The secretion of mesenchymal stem cells could not only improve neuroinflammation, but also exert a multi-target comprehensive therapeutic effect, making it potentially more suitable for the treatment of AD. Enhancing the level of TREM2 in microglial cells using gene editing technologies, or application of TREM2 antibodies such as Ab-T1, hT2AB could improve microglial cell function and reduce the level of neuroinflammation, which might be a potential treatment for AD. Probiotic therapy, fecal flora transplantation, antibiotic therapy, and dietary intervention could reshape the composition of the gut microbiota and alleviate neuroinflammation through the gut-brain axis. However, the drugs of sodium oligomannose remain controversial. Both exercise intervention and electromagnetic intervention had the potential to attenuate neuroinflammation, thereby delaying AD process. This article focuses on the role of drug therapy, gene therapy, stem cell therapy, gut microbiota therapy, exercise intervention, and brain stimulation in improving neuroinflammation in recent years, aiming to provide a novel insight for the treatment of AD by intervening neuroinflammation in the future.

Objective : To explore the mechanism of isorhamnetin (Iso) in the treatment of oral squamous cell carcinoma (OSCC) using network pharmacology and molecular docking methods and to verify it in vitro. Methods : The key targets were obtained by constructing the PPI protein interaction network based on the common intersection targets of Iso-OSCC. At the same time, gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) were used to analyze the related signaling pathways of the intersection targets. Iso and core targets were also analyzed through molecular docking and visualization. Colony formation assay and Transwell assay were used to identify the effect of Iso on the proliferation and invasion of Cal-27 cells. Western blot was used to analyze the regulatory effects of different concentrations of Iso on estrogen receptor-1 (ESR1), phosphoinositide-3-kinase regulatory subunit-1 (PIK3R1), Src tyrosine kinase (SRC), and phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway proteins. Results: A total of 269 potential intersection targets of Iso-regulated OSCC were obtained. According to the degree obtained by topological analysis, PIK3R1, AKT1, SRC, ESR1, and other core targets were screened out. KEGG analysis showed that 165 signaling pathways were enriched in the intersection targets of Iso-OSCC, among which the PI3K/AKT signaling pathway played an important role in the treatment of OSCC with Iso. Molecular docking results showed that the absolute value of binding energy between target proteins PIK3R1, AKT1, SRC, ESR1, and Iso was high. After Cal-27 cells were treated with Iso, the number of cell colony formations, the number of transmembrane cells, and the expression of PIK3R1, ESR1, SRC, p-PI3K, and p-AKT were negatively correlated with the increase in Iso concentration (P < 0.05). Conclusion Iso can inhibit PI3K/AKT signal transduction and influence the expression of PIK3R1, AKT1, SRC, and ESR1 proteins, thereby inhibiting the occurrence and development of OSCC.

Objective To investigate the clinical characteristics of patients with clinical and subclinical Cushing's syndrome caused by primary bilateral macronodular adrenal hyperplasia(PBMAH).Methods A retrospective analysis was performed on the clinical data of 198 patients with Cushing's syndrome caused by PBMAH diagnosed in the First Medical Center of Chinese PLA General Hospital from January 2004 to October 2024.According to clinical manifestations,the patients were classified into clinical type Cushing's syndrome(n=61)and subclinical type Cushing's syndrome(n=137),and the clinical characteristics of the two types were compared.Results The mean age at diagnosis of patients with PBMAH-induced Cushing's syndrome was(53.5±10.4)years,including 118 males and 80 females,with a male-to-female ratio of 1.475:1.Compared with the subclinical type,the clinical type had a higher proportion of females,higher levels of serum cortisol,24-hour urine free cortisol(24 h UFC),and inhibited serum cortisol after low-dose dexamethasone suppression.Additionally,the clinical type had lower plasma ACTH,larger adrenal nodules and a higher risk of surgery(P<0.05)compared with those in subclinical type.The incidences of hypertension,dyslipidemia,obesity,diabetes mellitus,hypokalemia,vitamin D deficiency,osteoporosis,coronary heart disease,and cerebrovascular disease in patients with Cushing's syndrome caused by PBMAH were 87.9%,50.5%,37.1%,36.9%,27.8%,25.9%,18.7%,18.7%and 12.1%,respectively.Among them,compared with subclinical type patients,clinical type patients had higher incidence of hypokalaemia,vitamin D deficiency and osteoporosis(P<0.05),while there were no statistically significant differences in the incidences of other comorbidities between the two types(P>0.05).The results of postoperative follow-up for PBMAH patients showed that the short-term biochemical remission rate of unilateral total adrenalectomy was 41.5%(22/53)and the long-term biochemical remission rate was 32.0%(8/25).The short-term biochemical remission rate of unilateral partial(or nodular)adrenalectomy was 52.9%(9/17),and the long-term biochemical remission rate was 14.3%(1/7).All patients who underwent unilateral total adrenalectomy plus contralateral partial resection developed adrenal insufficiency(3/3),and 1 patient(1/3)relapsed 3.4 years after surgery.Conclusion Clinical and subclinical types of Cushing's syndrome caused by PBMAH have their distinct clinical characteristics.Surgery is an effective treatment for PBMAH,but a certain proportion of patients fail to achieve biochemical remission after non-bilateral total adrenalectomy.

Objective To analyze the basic conditions and pathological characteristics of the samples in the Human Brain Bank of Hebei Medical University,which were pathologically diagnosed as cerebral amyloid angiopathy,and to provide reference for the research of related diseases.Methods The basic data of gender,age,apolipoprotein E genotype,pathological classification of cerebral amyloid angiopathy,Alzheimer's disease-related pathological change score,comorbidities and other pathological information were analyzed.Results Up to October 2024,twenty samples were confirmed by pathological diagnosis,with a male to female ratio of 3:1 and an average age of(80.90±8.08)years.Involve three kinds of apolipoprotein E subtype,5 kinds of genotypes(ε2/ε3 xε2/ε4、ε3/ε3 xε3/ε4、ε4/ε4);There were 2 pathologic types,including 6 cases of type 1 and 14 cases of type 2.The pathological grade included 3 grades.The severity grade and subtype classification of cerebral amyloid vascular disease were correlated with the degree of pathological changes of Alzheimer's disease.Cerebral amyloid angiopathy samples could coexist with other degenerative diseases with high comorbidity.Conclusion The incidence of cerebral amyloid angiopathy is higher in the aged samples collected based on Brain Bank,which coexists with conditions such as Alzheimer's disease and microbleeds,etc.It provides more detailed pathological diagnosis basis for further scientific research sharing of samples.