BACKGROUND: Urolithiasis is a widespread disease with a high prevalence worldwide. This study aims to evaluate the disease burden of urolithiasis and its trends from 1990 to 2021 globally, based on the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 database. METHODS: The numbers and age-standardized rates (ASRs) of incidence, disability-adjusted life years (DALYs), and mortality of urolithiasis were extracted from GBD 2021 to represent the disease burden. Joinpoint regression analyses were conducted to assess the temporal trends in the burden of urolithiasis. The male-to-female ASR ratio indices were used to evaluate sex disparities. Additionally, we explored the relationship between the ASR ratio and the sociodemographic index (SDI). RESULTS: The total numbers of incidence, DALY, and mortality of urolithiasis were 105,983,780 cases (95% uncertainty interval [UI] = 88,349,356-128,645,155 cases), 693,444 cases (95% UI = 567,765-850,490 cases), and 17,672 cases (95% UI = 13,932-21,241 cases), respectively, in 2021. There is an increasing trend in the number of these measures globally, whereas the ASRs have decreased over the past 30 years. The age-standardized incidence rate (ASIR) and age-standardized mortality rate (ASMR) were significantly higher in males than in females in 2021. The sex disparities in the age-standardized DALY rate (ASDR) and ASMR of urolithiasis were negatively correlated with the SDI. In 2021, the ASIR of urolithiasis was 964.70 (95% UI = 801.26-1175.09) per 100,000 people in China, which is much lower than the global average (1242.84 [95% UI = 1034.94-1506.99] per 100,000 people). Compared with the global average, a more pronounced decline in ASIR was observed in China from 1793.16 (1446.0-2235.14) in 1990 to 964.70 (801.26-1175.09) per 100,000 people in 2021. CONCLUSIONS Urolithiasis poses a significant healthcare burden worldwide. More robust global and national strategies are warranted to address the prevention and treatment, especially in low SDI countries and regions.
Humans ; Urolithiasis/mortality* ; Male ; Female ; Incidence ; Global Burden of Disease ; Disability-Adjusted Life Years ; Adult ; Middle Aged ; Risk Factors ; Sex Factors

Photodynamic immunotherapy is a promising strategy for cancer treatment. However, the dysfunctional tumor vasculature results in tumor hypoxia and the low efficiency of drug delivery, which in turn restricts the anticancer effect of photodynamic immunotherapy. In this study, we designed photosensitive lipid nanoparticles. The synthesized PFBT@Rox Lip nanoparticles could produce type I/II reactive oxygen species (ROS) by electron or energy transfer through PFBT under light irradiation. Moreover, this nanosystem could alleviate tumor hypoxia and promote vascular normalization through Roxadustat. Upon irradiation with white light, the ROS produced by PFBT@Rox Lip nanoparticles in situ dysregulated calcium homeostasis and triggered endoplasmic reticulum stress, which further promoted the release of damage-associated molecular patterns, enhanced antigen presentation, and stimulated an effective adaptive immune response, ultimately priming the tumor microenvironment (TME) together with the hypoxia alleviation and vessel normalization by Roxadustat. Indeed, in vivo results indicated that PFBT@Rox Lip nanoparticles promoted M1 polarization of tumor-associated macrophages, recruited more natural killer cells, and augmented infiltration of T cells, thereby leading to efficient photodynamic immunotherapy and potentiating the anti-primary and metastatic tumor efficacy of PD-1 antibody. Collectively, photodynamic immunotherapy with PFBT@Rox Lip nanoparticles efficiently program TME through the induction of immunogenicity and oxygenation, and effectively suppress tumor growth through immunogenic cell death and enhanced anti-tumor immunity.

With the growing emphasis on maternal and child oral health, the significance of managing oral health across preconception, pregnancy, and infancy stages has become increasingly apparent. Oral health challenges extend beyond affecting maternal well-being, exerting profound influences on fetal and neonatal oral development as well as immune system maturation. This expert consensus paper, developed using a modified Delphi method, reviews current research and provides recommendations on maternal and child oral health management. It underscores the critical role of comprehensive oral assessments prior to conception, diligent oral health management throughout pregnancy, and meticulous oral hygiene practices during infancy. Effective strategies should be seamlessly integrated across the life course, encompassing preconception oral assessments, systematic dental care during pregnancy, and routine infant oral hygiene. Collaborative efforts among pediatric dentists, maternal and child health workers, and obstetricians are crucial to improving outcomes and fostering clinical research, contributing to evidence-based health management strategies.
Humans ; Pregnancy ; Female ; Infant ; Consensus ; Mouth Diseases/therapy* ; Pregnancy Complications/therapy* ; Oral Health ; Infant, Newborn ; Delphi Technique ; Oral Hygiene

Objective To investigate the effects of total flavonoids from Vine tea on the intestinal flora of high-fat diet(HFD)induced non-alcoholic fatty liver disease(NAFLD)mice.Methods Twenty-eight mice were randomly divided into four groups:blank control group,model control group(HFD group),low-dose TF group(TF-L group),and high-dose TF group(TF-H group),with 7 mice in each group.Mice in the HFD group,TF-L group,and TF-H group were fed with high-fat diet(HFD)for 12 weeks,while those in the blank control group were fed a normal diet.After 12 weeks of high-fat diet feeding,mice in the TF-L group and TF-H group were orally administered TF solution at doses of 125 and 250 mg·kg-1·d-1 by gavage administration for 6 weeks of intervention.Pathological changes in the liver and intestine of mice were observed using hematoxylin-eosin(H&E)staining,and the expression levels of tight junction proteins between the epithelial cells of the colonic mucosa was analyzed by immunohistochemistry.ELISA kit was used to detect the level of serum inflammatory factors in mice.Changes of intestinal flora in mice were analyzed by 16S rRNA sequencing technology.Results Total flavonoids from Vine tea could effectively improve the pathological changes of liver and intestinal tract in mice,reduce the levels of serum inflammatory factors IL-6 and TNF-α,and promote the expression of tight junction proteins Occludin,ZO-1 and Claudin 1 in the colon.There were significant differences in the intestinal flora of the three groups of mice.Total flavonoids from Vine tea significantly decreased the ratio of Firmicutes to Bacteroidota(P＜0.05),increased the abundance of Faecalibaculum,Ligilactobacillus and Lactobacillus,which resulted in the improvement of intestinal flora disorders.Conclusion Total flavonoids from Vine tea have certain ameliorative effects on high-fat diet-induced NAFLD,and the mechanism may be related to the promotion of intestinal barrier repair and the improvement of intestinal flora disorders.

Objective:To investigate the iodine nutrition status of children aged 8 to 10 years old in Nanchang City.Methods:From March 2020 to September 2022, 9 counties (districts, administration bureau) in Nanchang City were selected as monitoring points. Each monitoring point was divided into 5 sampling areas according to the east, west, south, north, and middle directions. One township was selected from each area, and 40 non-boarding children aged 8 to 10 years old (age balanced, half male and half female) from one primary school were selected as survey subjects. Edible salt samples from children's homes, as well as a random urine sample were collected to detect salt iodine and urinary iodine level. The thyroid volume of children was also measured.Results:From 2020 to 2022, a total of 5 400 edible salt samples from children's homes were tested, with a median salt iodine level of 24.13 mg/kg. Among them, there were 5 172 qualified iodized salt samples, 168 unqualified iodized salt samples, and 60 non-iodized salt samples. The coverage rate of iodized salt was 98.89% (5 340/5 400), the qualified rate of iodized salt was 96.85% (5 172/5 340), and the consumption rate of qualified iodized salt was 95.78% (5 172/5 400). A total of 5 400 children's urine samples were tested, with a median urinary iodine level of 210.90 μg/L. A total of 2 662 children were examined for thyroid, of which 4 had thyroid enlargement, with an enlargement rate of 0.15% (4/2 662).Conclusion:The overall iodine nutrition of children aged 8 to 10 years old in Nanchang City is at a super appropriate level, and the thyroid enlargement rate meets the national standard (< 5%).

Objective:To elucidate the primary elements pertaining to the perception of relapse risk and to in-vestigate the characteristics and alterations of perception of the risk of recurrence in patients with schizophrenia.Methods:By using the method of phenomenological study,semi-structured in-depth interviews were conducted among schizophrenic patients with first onset,first recurrence and multiple recurrences.Twenty-three 23 outpatient and inpatient cases that met the criteria of the Diagnostic and Statistical Manual of Mental Disorders,Fifth Edition(DSM-5)were included,and all patients had PANSS scores below 60.The interview data were collated and analyzed according to Colaizzi analysis.Results:The perception of recurrence risk in patients with schizophrenia en-compassed 4 major themes and 11 sub-themes,namely susceptibility(limited overall understanding,transition from optimism to objectivity),detection of early warning symptoms(dynamic escalation,assistance from family mem-bers in identification),understanding risk factors(lack of understanding,the relationship between psychosocial fac-tors and relapse,dynamic understanding of medication-relapse relationship),and apprehension of the consequences of recurrence(care burden and financial constraints,impaired social functioning and maladjustment,impact on pub-lic safety,personal health risks).Conclusion:The content of risk perception of recurrence in patients with schizo-phrenia is relatively substantial.The overall level of risk perception of recurrence in patients with schizophrenia is low.

Objective:To report the long-term outcomes of Chinese rectal cancer patients after adopting a Watch and Wait (W&W) strategy following neoadjuvant therapy (NAT).Methods:This multicenter, cross-sectional study was based on real-world data. The study cohort comprised rectal cancer patients who had achieved complete or near complete clinical responses (cCRs, near-cCRs) after NAT and were thereafter managed by a W&W approach, as well as a few patients who had achieved good responses after NAT and had then undergone local excision for confirmation of pathological complete response. All participants had been followed up for ≥2 years. Patients with distant metastases at baseline or who opted for observation while living with the tumor were excluded. Data of eligible patients were retrospectively collected from the Chinese Wait-and-Watch Data Collaboration Group database. These included baseline characteristics, type of NAT, pre-treatment imaging results, evaluation of post-NAT efficacy, salvage measures, and treatment outcomes. We herein report the long-term outcomes of Chinese rectal cancer patients after NAT and W&W and the differences between the cCR and near-cCR groups.Results:Clinical data of 318 rectal cancer patients who had undergone W&W for over 2 years and been followed up were collected from eight medical centers (Peking University Cancer Hospital, Fudan University Shanghai Cancer Center, Sun Yat-sen University Cancer Center, Shanghai Changhai Hospital, Peking Union Medical College Hospital, Liaoning Cancer Hospital, the First Hospital of Jilin University, and Yunnan Cancer Hospital.) The participants comprised 221 men (69.4%) and 107 women (30.6%) of median age 60 (26-86) years. The median distance between tumor and anal verge was 3.4 (0-10.4) cm. Of these patients, 291 and 27 had achieved cCR or near-cCR, respectively, after NAT. The median duration of follow-up was 48.4 (10.2-110.3) months. The 5-year cumulative overall survival rate was 92.4% (95%CI: 86.8%-95.7%), 5-year cumulative disease-specific survival (CSS) rate 96.6% (95%CI: 92.2%-98.5%), 5-year cumulative organ-preserving disease-free survival rate 86.6% (95%CI: 81.0%-90.7%), and 5-year organ preservation rate 85.3% (95%CI: 80.3%-89.1%). The overall 5-year local recurrence and distant metastasis rates were 18.5% (95%CI: 14.9%-20.8%) and 8.2% (95%CI: 5.4%-12.5%), respectively. Most local recurrences (82.1%, 46/56) occurred within 2 years, and 91.0% (51/56) occurred within 3 years, the median time to recurrence being 11.7 (2.5-66.6) months. Most (91.1%, 51/56) local recurrences occurred within the intestinal lumen. Distant metastases developed in 23 patients; 60.9% (14/23) occurred within 2 years and 73.9% (17/23) within 3 years, the median time to distant metastasis being 21.9 (2.6-90.3) months. Common sites included lung (15/23, 65.2%), liver (6/23, 26.1%), and bone (7/23, 30.4%) The metastases involved single organs in 17 patients and multiple organs in six. There were no significant differences in overall, cumulative disease-specific, or organ-preserving disease-free survival or rate of metastases between the two groups (all P>0.05). The 5-year local recurrence rate was higher in the near-cCR than in the cCR group (41.6% vs. 16.4%, P<0.01), with a lower organ preservation rate (69.2% vs. 88.0%, P<0.001). The success rates of salvage after local recurrence and distant metastasis were 82.1% (46/56) and 13.0% (3/23), respectively. Conclusion:Rectal cancer patients who achieve cCR or near-cCR after NAT and undergo W&W have favorable oncological outcomes and a high rate of organ preservation. Local recurrence and distant metastasis during W&W follow certain patterns, with a relatively high salvage rate for local recurrence. Our findings highlight the importance of close follow-up and timely intervention during the W&W process.

Objective:To investigate perspectives and changes in treatment selection by Chinese surgeons since introduction of the watch-and-wait approach after neoadjuvant therapy for rectal cancer.Methods:A cross-sectional survey was conducted using a questionnaire distributed through the "Wenjuanxing" online survey platform. The survey focused on the recognition and practices of Chinese surgeons regarding the strategy of watch-and-wait after neoadjuvant therapy for rectal cancer and was disseminated within the China Watch-and-Wait Database (CWWD) WeChat group. This group targets surgeons of deputy chief physician level and above in surgical, radiotherapy, or internal medicine departments of nationally accredited tumor-specialist or comprehensive hospitals (at provincial or municipal levels) who are involved in colorectal cancer diagnosis and treatment. From 13 to 16 December 2023, 321 questionnaires were sent with questionnaire links in the CWWD WeChat group. The questionnaires comprised 32 questions encompassing: (1) basic physician characteristics (including surgical volume); (2) assessment methods and criteria for clinical complete response (cCR); (3) patients eligible for watch-and-wait; (4) neoadjuvant therapies and other measures for achieving cCR; (5) willingness to implement watch-and-wait and factors influencing that willingness; (6) risks and monitoring of watch-and-wait; (7) subsequent treatment and follow-up post watch-and-wait; (8) suggestions for development of the CWWD. Descriptive statistics were employed for data analysis, with intergroup comparisons conducted using the χ 2 or Fisher's exact probability tests. Results:The response rate was 31.5%, comprising 101 responses from the 321 individuals in the WeChat group. Respondents comprised 101 physicians from 70 centers across 23 provinces, municipalities, and autonomous regions nationwide, 85.1% (86/101) of whom represented provincial tertiary hospitals. Among the respondents, 87.1% (88/101) had implemented the watch-and-wait strategy. The approval rate (65.6%, 21/32) and proportion of patients often informed (68.8%, 22/32) were both significantly higher for doctors in oncology hospitals than for those in general hospitals (27.7%, 18/65; 32.4%, 22/68) (χ 2=12.83, P<0.001; χ 2=11.70, P=0.001, respectively). The most used methods for diagnosing cCR were digital rectal examination (90.1%, 91/101), colonoscopy (91.1%, 92/101), and rectal T2-weighted magnetic resonance imaging (86.1%, 87/101). Criteria used to identify cCR comprised absence of a palpable mass on digital rectal examination (87.1%, 88/101), flat white scars or new capillaries on colonoscopy (77.2%, 78/101), absence of evident tumor signals on rectal T2-weighted sequences or T2WI low signals or signals equivalent to the intestinal wall (83.2%, 84/101), and absence of tumor hyperintensity on diffusion-weighted imaging with no corresponding hypointensity on apparent diffusion coefficient maps (66.3%, 67/101). As for selection of neoadjuvant regimen and assessment of cCR, 57.4% (58/101) of physicians preferred a long course of radiotherapy with or without induction and/or consolidation capecitabine + oxaliplatin, whereas 25.7% (26/101) preferred immunotherapy in combination with chemotherapy and concurrent radiotherapy. Most (96.0%, 97/101) physicians believed that the primary lesion should be assessed ≤12 weeks after completion of radiotherapy. Patients were frequently informed about the possibility of achieving cCR after neoadjuvant therapy and the strategy of watch-and-wait by 43.6% (44/101) of the responding physicians and 38.6% (39/101) preferred watch-and-wait for patients who achieved cCR or near cCR after neoadjuvant therapy for rectal cancer. Capability for multiple follow-up evaluations (70.3%, 71/101) was a crucial factor influencing physicians' choice of watch-and-wait after cCR. The proportion who patients who did not achieve cCR and underwent surgical treatment was lower in provincial tertiary hospitals (74.2%, 23/31) than in provincial general hospitals (94.5%, 52/55) and municipal hospitals (12/15); these differences are statistically significant (χ 2=7.43, P=0.020). The difference between local recurrence and local regrowth was understood by 88.1% (89/101) of respondents and 87.2% (88/101) agreed with monitoring every 3 months for 5 years. An increase in local excision or puncture rates to reduce organ resections in patients with pCR was proposed by 64.4% (65/101) of respondents. Conclusion:Compared with the results of a previous survey, Chinese surgeons' awareness of the watch-and-wait concept has improved significantly. Oncologists in oncology hospitals are more aware of the concept of watch-and-wait.

Objective:To report the long-term outcomes of Chinese rectal cancer patients after adopting a Watch and Wait (W&W) strategy following neoadjuvant therapy (NAT).Methods:This multicenter, cross-sectional study was based on real-world data. The study cohort comprised rectal cancer patients who had achieved complete or near complete clinical responses (cCRs, near-cCRs) after NAT and were thereafter managed by a W&W approach, as well as a few patients who had achieved good responses after NAT and had then undergone local excision for confirmation of pathological complete response. All participants had been followed up for ≥2 years. Patients with distant metastases at baseline or who opted for observation while living with the tumor were excluded. Data of eligible patients were retrospectively collected from the Chinese Wait-and-Watch Data Collaboration Group database. These included baseline characteristics, type of NAT, pre-treatment imaging results, evaluation of post-NAT efficacy, salvage measures, and treatment outcomes. We herein report the long-term outcomes of Chinese rectal cancer patients after NAT and W&W and the differences between the cCR and near-cCR groups.Results:Clinical data of 318 rectal cancer patients who had undergone W&W for over 2 years and been followed up were collected from eight medical centers (Peking University Cancer Hospital, Fudan University Shanghai Cancer Center, Sun Yat-sen University Cancer Center, Shanghai Changhai Hospital, Peking Union Medical College Hospital, Liaoning Cancer Hospital, the First Hospital of Jilin University, and Yunnan Cancer Hospital.) The participants comprised 221 men (69.4%) and 107 women (30.6%) of median age 60 (26-86) years. The median distance between tumor and anal verge was 3.4 (0-10.4) cm. Of these patients, 291 and 27 had achieved cCR or near-cCR, respectively, after NAT. The median duration of follow-up was 48.4 (10.2-110.3) months. The 5-year cumulative overall survival rate was 92.4% (95%CI: 86.8%-95.7%), 5-year cumulative disease-specific survival (CSS) rate 96.6% (95%CI: 92.2%-98.5%), 5-year cumulative organ-preserving disease-free survival rate 86.6% (95%CI: 81.0%-90.7%), and 5-year organ preservation rate 85.3% (95%CI: 80.3%-89.1%). The overall 5-year local recurrence and distant metastasis rates were 18.5% (95%CI: 14.9%-20.8%) and 8.2% (95%CI: 5.4%-12.5%), respectively. Most local recurrences (82.1%, 46/56) occurred within 2 years, and 91.0% (51/56) occurred within 3 years, the median time to recurrence being 11.7 (2.5-66.6) months. Most (91.1%, 51/56) local recurrences occurred within the intestinal lumen. Distant metastases developed in 23 patients; 60.9% (14/23) occurred within 2 years and 73.9% (17/23) within 3 years, the median time to distant metastasis being 21.9 (2.6-90.3) months. Common sites included lung (15/23, 65.2%), liver (6/23, 26.1%), and bone (7/23, 30.4%) The metastases involved single organs in 17 patients and multiple organs in six. There were no significant differences in overall, cumulative disease-specific, or organ-preserving disease-free survival or rate of metastases between the two groups (all P>0.05). The 5-year local recurrence rate was higher in the near-cCR than in the cCR group (41.6% vs. 16.4%, P<0.01), with a lower organ preservation rate (69.2% vs. 88.0%, P<0.001). The success rates of salvage after local recurrence and distant metastasis were 82.1% (46/56) and 13.0% (3/23), respectively. Conclusion:Rectal cancer patients who achieve cCR or near-cCR after NAT and undergo W&W have favorable oncological outcomes and a high rate of organ preservation. Local recurrence and distant metastasis during W&W follow certain patterns, with a relatively high salvage rate for local recurrence. Our findings highlight the importance of close follow-up and timely intervention during the W&W process.

Objective:To investigate perspectives and changes in treatment selection by Chinese surgeons since introduction of the watch-and-wait approach after neoadjuvant therapy for rectal cancer.Methods:A cross-sectional survey was conducted using a questionnaire distributed through the "Wenjuanxing" online survey platform. The survey focused on the recognition and practices of Chinese surgeons regarding the strategy of watch-and-wait after neoadjuvant therapy for rectal cancer and was disseminated within the China Watch-and-Wait Database (CWWD) WeChat group. This group targets surgeons of deputy chief physician level and above in surgical, radiotherapy, or internal medicine departments of nationally accredited tumor-specialist or comprehensive hospitals (at provincial or municipal levels) who are involved in colorectal cancer diagnosis and treatment. From 13 to 16 December 2023, 321 questionnaires were sent with questionnaire links in the CWWD WeChat group. The questionnaires comprised 32 questions encompassing: (1) basic physician characteristics (including surgical volume); (2) assessment methods and criteria for clinical complete response (cCR); (3) patients eligible for watch-and-wait; (4) neoadjuvant therapies and other measures for achieving cCR; (5) willingness to implement watch-and-wait and factors influencing that willingness; (6) risks and monitoring of watch-and-wait; (7) subsequent treatment and follow-up post watch-and-wait; (8) suggestions for development of the CWWD. Descriptive statistics were employed for data analysis, with intergroup comparisons conducted using the χ 2 or Fisher's exact probability tests. Results:The response rate was 31.5%, comprising 101 responses from the 321 individuals in the WeChat group. Respondents comprised 101 physicians from 70 centers across 23 provinces, municipalities, and autonomous regions nationwide, 85.1% (86/101) of whom represented provincial tertiary hospitals. Among the respondents, 87.1% (88/101) had implemented the watch-and-wait strategy. The approval rate (65.6%, 21/32) and proportion of patients often informed (68.8%, 22/32) were both significantly higher for doctors in oncology hospitals than for those in general hospitals (27.7%, 18/65; 32.4%, 22/68) (χ 2=12.83, P<0.001; χ 2=11.70, P=0.001, respectively). The most used methods for diagnosing cCR were digital rectal examination (90.1%, 91/101), colonoscopy (91.1%, 92/101), and rectal T2-weighted magnetic resonance imaging (86.1%, 87/101). Criteria used to identify cCR comprised absence of a palpable mass on digital rectal examination (87.1%, 88/101), flat white scars or new capillaries on colonoscopy (77.2%, 78/101), absence of evident tumor signals on rectal T2-weighted sequences or T2WI low signals or signals equivalent to the intestinal wall (83.2%, 84/101), and absence of tumor hyperintensity on diffusion-weighted imaging with no corresponding hypointensity on apparent diffusion coefficient maps (66.3%, 67/101). As for selection of neoadjuvant regimen and assessment of cCR, 57.4% (58/101) of physicians preferred a long course of radiotherapy with or without induction and/or consolidation capecitabine + oxaliplatin, whereas 25.7% (26/101) preferred immunotherapy in combination with chemotherapy and concurrent radiotherapy. Most (96.0%, 97/101) physicians believed that the primary lesion should be assessed ≤12 weeks after completion of radiotherapy. Patients were frequently informed about the possibility of achieving cCR after neoadjuvant therapy and the strategy of watch-and-wait by 43.6% (44/101) of the responding physicians and 38.6% (39/101) preferred watch-and-wait for patients who achieved cCR or near cCR after neoadjuvant therapy for rectal cancer. Capability for multiple follow-up evaluations (70.3%, 71/101) was a crucial factor influencing physicians' choice of watch-and-wait after cCR. The proportion who patients who did not achieve cCR and underwent surgical treatment was lower in provincial tertiary hospitals (74.2%, 23/31) than in provincial general hospitals (94.5%, 52/55) and municipal hospitals (12/15); these differences are statistically significant (χ 2=7.43, P=0.020). The difference between local recurrence and local regrowth was understood by 88.1% (89/101) of respondents and 87.2% (88/101) agreed with monitoring every 3 months for 5 years. An increase in local excision or puncture rates to reduce organ resections in patients with pCR was proposed by 64.4% (65/101) of respondents. Conclusion:Compared with the results of a previous survey, Chinese surgeons' awareness of the watch-and-wait concept has improved significantly. Oncologists in oncology hospitals are more aware of the concept of watch-and-wait.