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Featured researches published by Johan Ottosson.


Annals of Surgery | 2014

Early Complications After Laparoscopic Gastric Bypass Surgery : Results From the Scandinavian Obesity Surgery Registry

Erik Stenberg; Eva Szabo; Göran Ågren; Erik Näslund; Lars Boman; Ami Bylund; Jan Hedenbro; Anna Laurenius; Göran Lundegårdh; Hans Lönroth; Peter Möller; Magnus Sundbom; Johan Ottosson; Ingmar Näslund

Objective:To identify risk factors for serious and specific early complications of laparoscopic gastric bypass surgery using a large national cohort of patients. Background:Bariatric procedures are among the most common surgical procedures today. There is, however, still a need to identify preoperative and intraoperative risk factors for serious complications. Methods:From the Scandinavian Obesity Surgery Registry database, we identified 26,173 patients undergoing primary laparoscopic gastric bypass operation for morbid obesity between May 1, 2007, and September 30, 2012. Follow-up on day 30 was 95.7%. Preoperative data and data from the operation were analyzed against serious postoperative complications and specific complications. Results:The overall risk of serious postoperative complications was 3.4%. Age (adjusted P = 0.028), other additional operation [odds ratio (OR) = 1.50; confidence interval (CI): 1.04–2.18], intraoperative adverse event (OR = 2.63; 1.89–3.66), and conversion to open surgery (OR = 4.12; CI: 2.47–6.89) were all risk factors for serious postoperative complications. Annual hospital volume affected the rate of serious postoperative complications. If the hospital was in a learning curve at the time of the operation, the risk for serious postoperative complications was higher (OR = 1.45; CI: 1.22–1.71). The 90-day mortality rate was 0.04%. Conclusions:Intraoperative adverse events and conversion to open surgery are the strongest risk factors for serious complications after laparoscopic gastric bypass surgery. Annual operative volume and total institutional experience are important for the outcome. Patient related factors, in particular age, also increased the risk but to a lesser extent.


The Lancet Diabetes & Endocrinology | 2015

Cardiovascular disease and mortality in patients with type 2 diabetes after bariatric surgery in Sweden: a nationwide, matched, observational cohort study

Björn Eliasson; Vasileios Liakopoulos; Stefan Franzén; Ingmar Näslund; Ann-Marie Svensson; Johan Ottosson; Soffia Gudbjörnsdottir

BACKGROUND In patients with diabetes and obesity specifically, no studies have examined mortality after bariatric surgery. We did a nationwide study in Sweden to examine risks of cardiovascular disease and mortality in patients with obesity and diabetes who had undergone bariatric surgery (Roux-en-Y gastric bypass [RYGB]). METHODS In this nationwide, matched, observational cohort study, we merged data for patients who had undergone RYGB registered in the Scandinavian Obesity Surgery Registry with other national databases, and identified matched controls (on the basis of sex, age, BMI, and calendar time [year]) who had not undergone bariatric surgery from the National Diabetes Registry. We assessed risks of cardiovascular disease and death using a Cox proportional-hazards regression model and other methods to examine the treatment effect while accounting for residual confounding. Primary outcomes were total mortality, cardiovascular death, and fatal or non-fatal myocardial infarction. FINDINGS Between Jan 1, 2007, and Dec 31, 2014, we obtained data for 6132 patients who had undergone RYGB and 6132 control patients who had not. Median follow-up was 3·5 years (IQR 2·1-4·7). We noted a 58% relative risk reduction (hazard ratio [HR] 0·42, 95% CI 0·30-0·57; p<0·0001) in overall mortality in the RYGB group compared with the controls. The risk of fatal or non-fatal myocardial infarction was 49% lower (HR 0·51, 0·29-0·91; p=0·021) and that of cardiovascular death was 59% lower (0·41, 0·19-0·90; p=0·026) in the RYGB group than in the control group. 5 year absolute risks of death were 1·8% (95% CI 1·5-2·2) in the RYGB group and 5·8% (5·0-6·8) in the control group. INTERPRETATION Our findings provide support for the benefits of RYGB surgery for patients with obesity and type 2 diabetes. The causes of these beneficial effects may be the weight reduction per se, changes in physiology and metabolism, improved care and treatment, improvements in lifestyle and risk factors, or combinations of these factors. FUNDING Swedish Association of Local Authorities and Regions and Region Västra Götaland.


The Lancet | 2016

Closure of mesenteric defects in laparoscopic gastric bypass: a multicentre, randomised, parallel, open-label trial

Erik Stenberg; Eva Szabo; Göran Ågren; Johan Ottosson; Richard Marsk; Hans Lönroth; Lars Boman; Anders Magnuson; Anders Thorell; Ingmar Näslund

BACKGROUND Small bowel obstruction due to internal hernia is a common and potentially serious complication after laparoscopic gastric bypass surgery. Whether closure of surgically created mesenteric defects might reduce the incidence is unknown, so we did a large randomised trial to investigate. METHOD This study was a multicentre, randomised trial with a two-arm, parallel design done at 12 centres for bariatric surgery in Sweden. Patients planned for laparoscopic gastric bypass surgery at any of the participating centres were offered inclusion. During the operation, a concealed envelope was opened and the patient was randomly assigned to either closure of mesenteric defects beneath the jejunojejunostomy and at Petersens space or non-closure. After surgery, assignment was open label. The main outcomes were reoperation for small bowel obstruction and severe postoperative complications. Outcome data and safety were analysed in the intention-to-treat population. This trial is registered with ClinicalTrials.gov, number NCT01137201. FINDINGS Between May 1, 2010, and Nov 14, 2011, 2507 patients were recruited to the study and randomly assigned to closure of the mesenteric defects (n=1259) or non-closure (n=1248). 2503 (99·8%) patients had follow-up for severe postoperative complications at day 30 and 2482 (99·0%) patients had follow-up for reoperation due to small bowel obstruction at 25 months. At 3 years after surgery, the cumulative incidence of reoperation because of small bowel obstruction was significantly reduced in the closure group (cumulative probability 0·055 for closure vs 0·102 for non-closure, hazard ratio 0·56, 95% CI 0·41-0·76, p=0·0002). Closure of mesenteric defects increased the risk for severe postoperative complications (54 [4·3%] for closure vs 35 [2·8%] for non-closure, odds ratio 1·55, 95% CI 1·01-2·39, p=0·044), mainly because of kinking of the jejunojejunostomy. INTERPRETATION The results of our study support the routine closure of the mesenteric defects in laparoscopic gastric bypass surgery. However, closure of the mesenteric defects might be associated with increased risk of early small bowel obstruction caused by kinking of the jejunojejunostomy. FUNDING Örebro County Council, Stockholm City Council, and the Erling-Persson Family Foundation.


Circulation | 2017

Weight Loss and Heart Failure A Nationwide Study of Gastric Bypass Surgery Versus Intensive Lifestyle Treatment

Johan Sundström; Gustaf Bruze; Johan Ottosson; Claude Marcus; Ingmar Näslund; Martin Neovius

Background: Associations of obesity with incidence of heart failure have been observed, but the causality is uncertain. We hypothesized that gastric bypass surgery leads to a lower incidence of heart failure compared with intensive lifestyle modification in obese people. Methods: We included obese people without previous heart failure from a Swedish nationwide registry of people treated with a structured intensive lifestyle program and the Scandinavian Obesity Surgery Registry. All analyses used inverse probability weights based on baseline body mass index and a propensity score estimated from baseline variables. Treatment groups were well balanced in terms of weight, body mass index, and most potential confounders. Associations of treatment with heart failure incidence, as defined in the National Patient Register, were analyzed with Cox regression. Results: The 25 804 gastric bypass surgery patients had on average lost 18.8 kg more weight after 1 year and 22.6 kg more after 2 years than the 13 701 lifestyle modification patients. During a median of 4.1 years, surgery patients had lower heart failure incidence than lifestyle modification patients (hazard ratio, 0.54; 95% confidence interval, 0.36–0.82). A 10-kg achieved weight loss after 1 year was related to a hazard ratio for heart failure of 0.77 (95% confidence interval, 0.60–0.97) in both treatment groups combined. Results were robust in sensitivity analyses. Conclusions: Gastric bypass surgery was associated with approximately one half the incidence of heart failure compared with intensive lifestyle modification in this study of 2 large nationwide registries. We also observed a graded association between increasing weight loss and decreasing risk of heart failure.


The Lancet Diabetes & Endocrinology | 2018

Risk of suicide and non-fatal self-harm after bariatric surgery: results from two matched cohort studies

Martin Neovius; Gustaf Bruze; Peter Jacobson; Kajsa Sjöholm; Kari Johansson; Fredrik Granath; Johan Sundström; Ingmar Näslund; Claude Marcus; Johan Ottosson; Markku Peltonen; Lena M.S. Carlsson

SUMMARY BACKGROUND Bariatric surgery reduces mortality, but may have adverse effects on mental health. We assessed suicide risk after surgical compared to nonsurgical obesity treatment. METHODS Suicide and nonfatal self-harm events retrieved from nationwide Swedish registers were examined in two cohorts. The nonrandomised prospective Swedish Obese Subjects (SOS) study compares bariatric surgery (n=2010; 1369 vertical-banded gastroplasty, 376 gastric banding, 265 gastric bypass) with usual care (n=2037; recruitment 1987–2001). The second cohort comprises individuals from the Scandinavian Obesity Surgery Registry (SOReg; n=20,256 gastric bypass patients) matched to individuals treated with intensive lifestyle modification (n=16,162; intervention 2006–2013) on baseline BMI, age, sex, education level, diabetes, cardiovascular disease, history of self-harm, substance abuse, antidepressant use, anxiolytics use, and psychiatric healthcare contacts. FINDINGS During 68,528 person-years (median 18; interquartile range 14–21) in SOS, there were 87 versus 49 suicides or nonfatal self-harm events in the surgery and control groups (adjusted hazard ratio [aHR] 1.78 [95%CI 1.23–2.57]; P=0.0021), of which 9 and 3 were suicides (3.06 [0.79–11.9]; P=0.107). In analyses by primary procedure type, increased risk of suicide or nonfatal self-harm was observed for gastric bypass (aHR 3.48 *1.65–7.31+; P=0.0010), gastric banding (2.43 *1.23–4.82+; P=0.011) and vertical-banded gastroplasty compared to controls (2.25 *1.37–3.71+; P=0.0015). Out of 9 deaths by suicide in the SOS surgery group, 5 occurred after gastric bypass (2 primary and 3 converted procedures). During 149,582 person-years (median 3.9; interquartile range 2.8–5.2), there were 341 suicides or nonfatal self-harm events in the SOReg gastric bypass group and 84 in the intensive lifestyle group (aHR 3.16 [2.46–4.06]; P<0.0001), of which 33 and 5 were suicides (5.17 [1.86–14.4]; P=0.0017). In SOS, substance abuse was recorded in 48% (39/81) of surgery patients and 28% (13/47) of controls with nonfatal self-harm events (P=0.023). The corresponding percentages for SOReg gastric bypass and intensive lifestyle participants were 51% (162/316) versus 29% (23/80; P=0.0003). INTERPRETATION Bariatric surgery was associated with suicide and nonfatal self-harm. Although the absolute risks were low, the findings indicate a need for post-operative psychiatric surveillance and patient information before surgery regarding self-harm. FUNDING US National Institutes of Health and Swedish Research CouncilBACKGROUND Bariatric surgery reduces mortality, but might have adverse effects on mental health. We assessed the risk of suicide and self-harm after bariatric surgery compared with non-surgical obesity treatment. METHODS Suicide and non-fatal self-harm events retrieved from nationwide Swedish registers were examined in two cohorts. The non-randomised, prospective Swedish Obese Subjects (SOS) study compared bariatric surgery (n=2010; 1369 vertical-banded gastroplasty, 376 gastric banding, and 265 gastric bypass) with usual care (n=2037; recruitment 1987-2001). The second cohort consisted of individuals from the Scandinavian Obesity Surgery Registry (SOReg; n=20 256 patients who had gastric bypass) matched to individuals treated with intensive lifestyle modification (n=16 162; intervention 2006-13) on baseline BMI, age, sex, education level, diabetes, cardiovascular disease, history of self-harm, substance misuse, antidepressant use, anxiolytics use, and psychiatric health-care contacts. FINDINGS During 68 528 person-years (median 18; IQR 14-21) in the SOS study, suicides or non-fatal self-harm events were higher in the surgery group (n=87) than in the control group (n=49; adjusted hazard ratio [aHR] 1·78, 95% CI 1·23-2·57; p=0·0021); of these events, nine and three were suicides, respectively (3·06, 0·79-11·88; p=0·11). In analyses by primary procedure type, increased risk of suicide or non-fatal self-harm was identified for gastric bypass (3·48, 1·65-7·31; p=0·0010), gastric banding (2·43, 1·23-4·82; p=0·011), and vertical-banded gastroplasty (2·25, 1·37-3·71; p=0·0015) compared with controls. Out of nine deaths by suicide in the SOS surgery group, five occurred after gastric bypass (two primary and three converted procedures). During 149 582 person-years (median 3·9; IQR 2·8-5·2), more suicides or non-fatal self-harm events were reported in the SOReg gastric bypass group (n=341) than in the intensive lifestyle group (n=84; aHR 3·16, 2·46-4·06; p<0·0001); of these events, 33 and five were suicides, respectively (5·17, 1·86-14·37; p=0·0017). In SOS, substance misuse during follow-up was recorded in 48% (39/81) of patients treated with surgery and 28% (13/47) of controls with non-fatal self-harm events (p=0·023). Correspondingly, substance misuse during follow-up was recorded in 51% (162/316) of participants in the SOReg gastric bypass group and 29% (23/80) of participants in the intensive lifestyle group with non-fatal self-harm events (p=0·0003). The risk of suicide and self-harm was not associated with poor weight loss outcome. INTERPRETATION Bariatric surgery was associated with suicide and non-fatal self-harm. However, the absolute risks were low and do not justify a general discouragement of bariatric surgery. The findings indicate a need for thorough preoperative psychiatric history assessment along with provision of information about increased risk of self-harm following surgery. Moreover, the findings call for postoperative surveillance with particular attention to mental health. FUNDING US National Institutes of Health and Swedish Research Council.


Annals of Surgery | 2017

Substantial Decrease in Comorbidity 5 Years After Gastric Bypass: A Population-based Study From the Scandinavian Obesity Surgery Registry

Magnus Sundbom; Jakob Hedberg; Richard Marsk; Lars Boman; Ami Bylund; Jan Hedenbro; Anna Laurenius; Göran Lundegårdh; Peter Möller; Torsten Olbers; Johan Ottosson; Ingmar Näslund; Erik Näslund

Objective: To evaluate effect on comorbid disease and weight loss 5 years after Roux-en-Y gastric bypass (RYGB) surgery for morbid obesity in a large nationwide cohort. Background: The number patients having surgical procedures to treat obesity and obesity-related disease are increasing. Yet, population-based, long-term outcome studies are few. Methods: Data on 26,119 individuals [75.8% women, 41.0 years, and body mass index (BMI) 42.8 kg/m2] undergoing primary RYGB between May 1, 2007 and June 30, 2012, were collected from 2 Swedish quality registries: Scandinavian Obesity Surgery Registry and the Prescribed Drug Registry. Weight, remission of type 2 diabetes mellitus, hypertension, dyslipidemia, depression, and sleep apnea, and changes in corresponding laboratory data were studied. Five-year follow-up was 100% (9774 eligible individuals) for comorbid diseases. Results: BMI decreased from 42.8 ± 5.5 to 31.2 ± 5.5 kg/m2 at 5 years, corresponding to 27.7% reduction in total body weight. Prevalence of type 2 diabetes mellitus (15.5%–5.9%), hypertension (29.7%–19.5%), dyslipidemia (14.0%–6.8%), and sleep apnea (9.6%–2.6%) was reduced. Greater weight loss was a positive prognostic factor, whereas increasing age or BMI at baseline was a negative prognostic factor for remission. The use of antidepressants increased (24.1%–27.5%). Laboratory status was improved, for example, fasting glucose and glycated hemoglobin decreased from 6.1 to 5.4 mmol/mol and 41.8% to 37.7%, respectively. Conclusions: In this nationwide study, gastric bypass resulted in large improvements in obesity-related comorbid disease and sustained weight loss over a 5-year period. The increased use of antidepressants warrants further investigation.


Surgery for Obesity and Related Diseases | 2014

Aortic injuries during laparoscopic gastric bypass for morbid obesity in Sweden 2009–2010: A nationwide survey

Magnus Sundbom; Jakob Hedberg; Anders Wanhainen; Johan Ottosson

BACKGROUND In Sweden, bariatric surgery has increased more than tenfold in the past decade, from 700 to 8,600 procedures annually, and laparoscopic gastric bypass (LRYGB) dominates (92% of all procedures). This expansion makes safety issues crucial. The aim of this nationwide survey was to identify aortic injuries in LRYGB. METHODS All 41 centers performing LRYGB in Sweden were asked if an aortic injury had occurred during the years 2009-2010. Techniques for entering the first trocar and way of establishing pneumoperitoneum were evaluated. The total number of procedures was collected from the national quality registry, Scandinavian Obesity Surgery Registry (SOReg), and the National Patient Register. RESULTS During the study period, 11,744 LRYGBs were performed. The analysis revealed 5 aortic injuries, all occurring in patients in whom an optical trocar had been placed before establishing pneumoperitoneum. Outcomes varied from no major sequelae to bilateral lower limb amputation and death. Based on the total number of LRYGBs, the risk for an aortic injury was .043% overall and .091% when an optical trocar was used. CONCLUSION Aortic injury is a rare but serious complication in laparoscopic gastric bypass. In this survey, optical trocars constructed to reduce the risk of intraabdominal damage had been used in all 5 cases.


JAMA Surgery | 2018

Associations of Bariatric Surgery With Changes in Interpersonal Relationship Status: Results From 2 Swedish Cohort Studies

Gustaf Bruze; Tobias E. Holmin; Markku Peltonen; Johan Ottosson; Kajsa Sjöholm; Ingmar Näslund; Martin Neovius; Lena M.S. Carlsson; Per-Arne Svensson

Importance Bariatric surgery is a life-changing treatment for patients with severe obesity, but little is known about its association with interpersonal relationships. Objectives To investigate if relationship status is altered after bariatric surgery. Design, Setting, and Participants Changes in relationship status after bariatric surgery were examined in 2 cohorts: (1) the prospective Swedish Obese Subjects (SOS) study, which recruited patients undergoing bariatric surgery from September 1, 1987, to January 31, 2001, and compared their care with usual nonsurgical care in matched obese control participants; and (2) participants from the Scandinavian Obesity Surgery Registry (SOReg), a prospective, electronically captured register that recruited patients from January 2007 through December 2012 and selected comparator participants from the general population matched on age, sex, and place of residence. Data was collected in surgical departments and primary health care centers in Sweden. The current analysis includes data collected up until July 2015 (SOS) and December 2012 (SOReg). Data analysis was completed from June 2016 to December 2017. Main Outcomes and Measures In the SOS study, information on relationship status was obtained from questionnaires. In the SOReg and general population cohort, information on marriage and divorce was obtained from the Swedish Total Population Registry. Results The SOS study included 1958 patients who had bariatric surgery (of whom 1389 [70.9%] were female) and 1912 matched obese controls (of whom 1354 [70.8%] were female) and had a median (range) follow-up of 10 (0.5-20) years. The SOReg cohort included 29 234 patients who had gastric bypass surgery (of whom 22 131 [75.6%] were female) and 283 748 comparators from the general population (of whom 214 342 [75.5%] were female), and had a median (range) follow-up of 2.9 (0.003-7.0) years. In the SOS study, the surgical patients received gastric banding (n = 368; 18.8%), vertical banded gastroplasty (n = 1331; 68.0%), or gastric bypass (n = 259; 13.2%); controls received usual obesity care. In SOReg, all 29 234 surgical participants received gastric bypass surgery. In the SOS study, bariatric surgery was associated with increased incidence of divorce/separation compared with controls for those in a relationship (adjusted hazard ratio [aHR] = 1.28; 95% CI, 1.03-1.60; P = .03) and increased incidence of marriage or new relationship (aHR = 2.03; 95% CI, 1.52-2.71; P < .001) in those who were unmarried or single at baseline. In the SOReg and general population cohort, gastric bypass was associated with increased incidence of divorce compared with married control participants (aHR = 1.41; 95% CI, 1.33-1.49; P < .001) and increased incidence of marriage in those who were unmarried at baseline (aHR = 1.35; 95% CI, 1.28-1.42; P < .001). Within the surgery groups, changes in relationship status were more common in those with larger weight loss. Conclusions and Relevance In addition to its association with obesity comorbidities, bariatric surgery–induced weight loss is also associated with changes in relationship status.


Surgery for Obesity and Related Diseases | 2017

Cholecystectomy after gastric bypass—incidence and complications

Viktor Wanjura; Gabriel Sandblom; Johanna Österberg; Lars Enochsson; Johan Ottosson; Eva Szabo

BACKGROUND Although cholecystectomy incidence is known to be high after Roux-en-Y gastric bypass (RYGB) surgery, the actual increase in incidence is not known. Furthermore, the outcome of cholecystectomy after RYGB is not known. OBJECTIVES To estimate cholecystectomy incidence before and after RYGB and to compare the outcome of post-RYGB cholecystectomy with the cholecystectomy outcome in the background population. SETTING Nationwide Swedish multiregister study. METHODS The Swedish Register for Cholecystectomy and Endoscopic Retrograde Cholangiopancreatography (n = 79,386) and the Scandinavian Obesity Surgery Registry (n = 36,098) were cross-matched for the years 2007 through 2013 and compared with the National Patient Register. RESULTS The standardized incidence ratio for cholecystectomy before RYGB was 3.42 (2.75-4.26, P<.001); the ratio peaked at 11.4 (10.2-12.6, P<.001) 6-12 months after RYGB, which was 3.54 times the baseline level (2.78-4.49, P<.001). After 36 months, the incidence ratio had returned to baseline. The post-RYGB group demonstrated an increased risk of 30-day postoperative complications after cholecystectomy (odds ratio 2.13, 1.78-2.56; P<.001), including reoperation (odds ratio 3.84, 2.76-5.36; P<.001), compared with the background population. The post-RYGB group also demonstrated a higher risk of conversion, acute cholecystectomy, and complicated gallstone disease and a slightly prolonged operative time, adjusted for age, sex, American Society of Anesthesiologists class, and previous open RYGB. CONCLUSION Compared with the background population, the incidence of cholecystectomy was substantially elevated already before RYGB and increased further 6-36 months after RYGB. Previous RYGB doubled the risk of postoperative complications after cholecystectomy and almost quadrupled the risk of reoperation, even when intraoperative cholangiography was normal.


Surgery for Obesity and Related Diseases | 2017

Hospital admission after gastric bypass: a nationwide cohort study with up to 6 years follow-up

Gustaf Bruze; Johan Ottosson; Martin Neovius; Ingmar Näslund; Richard Marsk

BACKGROUND Several studies have addressed short-term admission rates after bariatric surgery. However, studies on long-term admission rates are few and population based studies are even scarcer. OBJECTIVE The aim of this study was to assess short- and long-term admission rates for gastrointestinal surgery after gastric bypass in Sweden compared with admission rates in the general population. SETTING Swedish healthcare system. METHODS The surgery cohort consisted of adults with body mass index≥35 identified in the Scandinavian Obesity Surgery Registry (n = 28,331; mean age 41 years; 76% women; Roux-en-Y gastric bypass performed 2007-2012). For each individual, up to 10 comparators from the general population were matched on birth year, sex, and place of residence (n = 274,513). The primary outcome was inpatient admissions due to gastrointestinal surgery retrieved from the National Patient Register through December 31, 2014. Conditional hazard ratios (HR) were estimated using Cox regression. RESULTS All-cause admission rates were 6.5%, 21.4%, and 65.9% during 30 days, 1 year, and 6 years after surgery, respectively. The corresponding rates for gastrointestinal surgery were 1.8%, 6.8%, and 24.4%. Compared with that of the general population, there was an increased risk of all-cause hospital admission at 1 year (HR 2.6 [2.5-2.6]) and 6 years (HR 2.7 [2.6-2.7]). The risk of hospital admission for any gastrointestinal surgical procedure was greatly increased throughout the study period (HR 8.6 [8.4-8.9]). Female sex, psychiatric disease, and low education were risk factors. CONCLUSION We found a significant risk of admission to hospital over>6 years after gastric bypass surgery.

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