Revealing the CO2 Conversion at Electrode/Electrolyte Interfaces in Li-CO2 Batteries via Nanoscale Visualization Methods.

Lithium-carbon dioxide (Li-CO2 ) battery technology presents a promising opportunity for carbon capture and energy storage. Despite tremendous efforts in Li-CO2 batteries, the complex electrode/electrolyte/CO2 triple-phase interfacial processes remain poorly understood, in particular at the nanoscale. Here, using in situ atomic force microscopy and laser confocal microscopy-differential interference contrast microscopy, we directly observed the CO2 conversion processes in Li-CO2 batteries at the nanoscale, and further revealed a laser-tuned reaction pathway based on the real-time observations. During discharge, a bi-component composite, Li2 CO3 /C, deposits as micron-sized clusters through a 3D progressive growth model, followed by a 3D decomposition pathway during the subsequent recharge. When the cell operates under laser (λ=405 nm) irradiation, densely packed Li2 CO3 /C flakes deposit rapidly during discharge. Upon the recharge, they predominantly decompose at the interfaces of the flake and electrode, detaching themselves from the electrode and causing irreversible capacity degradation. In situ Raman shows that the laser promotes the formation of poorly soluble intermediates, Li2 C2 O4 , which in turn affects growth/decomposition pathways of Li2 CO3 /C and the cell performance. Our findings provide mechanistic insights into interfacial evolution in Li-CO2 batteries and the laser-tuned CO2 conversion reactions, which can inspire strategies of monitoring and controlling the multistep and multiphase interfacial reactions in advanced electrochemical devices.

Comparison of embryo implantation potential between time-lapse incubators and standard incubators: a randomized controlled study.

RESEARCH QUESTION: What are the potential clinical benefits of embryo culture and assessment in a time-lapse incubator compared with a standard incubator using static assessment? DESIGN: This large multicentre, single-blinded, randomized controlled study included 1224 participants randomly assigned (1:1) to the time-lapse or standard incubator group. In all patients one or two embryos were transferred on day 3. The primary outcome was the implantation rate in the first embryo transfer cycle. Secondary outcomes included the cumulative implantation rate, live birth rate in the first embryo transfer cycle and cumulative live birth rate. RESULTS: Among 1224 participants recruited, 1182 underwent embryo transfer. The number of successfully implanted embryos in the first transfer cycle was significantly higher in the time-lapse incubator group (time-lapse group: 52.35%, standard incubator group: 47.11%, P = 0.014). The implantation rate in the first embryo transfer cycle was still significantly higher in the time-lapse group than the standard incubator group after adjusting for age, body mass index, medical centre and embryo status (relative risk 1.11, 95% confidence interval 1.02-1.20, P = 0.020). However, the cumulative implantation rate, live birth rate in the first embryo transfer cycle and cumulative live birth rate were not statistically different between the groups. CONCLUSIONS: The implantation rate in the first embryo transfer cycle was significantly improved in the time-lapse group, but the effect of the time-lapse system on the cumulative implantation rate or cumulative live birth rate was not significant. The embryo assessment method offered by time-lapse systems rather than an undisturbed environment may play an important role in improving the implantation rate in the first embryo transfer cycle. These results are only applicable to young patients.

Clinical Application of Chromosomal Microarray Analysis in Pregnant Women with Advanced Maternal Age and Fetuses with Ultrasonographic Soft Markers.

BACKGROUND In pregnant women with advanced maternal age (AMA) and fetuses with ultrasonographic (USG) soft markers it is always challenging to decide whether to implement chromosomal microarray analysis (CMA) or not. It is unclear whether CMA should be used in the fetuses with isolated USG soft markers, and there is still a lack of extensive sample research. MATERIAL AND METHODS We enrolled 1521 cases in our research and divided them into 3 groups as follows: pregnant women with isolated AMA (group 1, n=633), pregnant women whose fetuses had isolated USG soft markers (group 2, n=750), and pregnant women with AMA whose fetuses had isolated USG soft markers (group 3, n=138). All pregnant women underwent prenatal ultrasound and amniocentesis, and fetal cells in the amniotic fluid were used for genetic analysis of CMA. All participants signed a written informed consent prior to CMA. RESULTS Abnormal findings were detected by CMA in 330 (21.70%) fetuses, including 37 (2.43%) clinically significant copy number variations (CNVs), 52 (3.42%) benign or likely benign CNVs, and 240 (15.78%) variants of unknown significance. The frequency of clinically significant CNVs in group 1 and group 2 were significantly lower than that in group 3 (2.37% and 2.0% vs 5.07%, P<0.01). More than a half (59.46%, 22/37) of the pregnant women decided to continue their pregnancy despite having a fetus diagnosed with clinically significant CNV. CONCLUSIONS CMA can increase the diagnostic yield of fetal chromosomal abnormality for pregnant women with isolated AMA or/and their fetuses had isolated USG soft markers.

Natural Transmission of b2/b3 Subdeletion or Duplication to Expanded Y Chromosome Microdeletions.

BACKGROUND Y chromosome microdeletions are usually de novo mutations, but in several cases, transmission from fertile fathers to infertile sons has been reported. MATERIAL AND METHODS We report 3 cases of infertile patients who inherited expanded Y chromosome microdeletions from their fathers, who carried b2/b3 subdeletion or duplication. The karyotype was analyzed using G-banding. High-throughput sequencing was used to detect AZF region microdeletions. RESULTS Cytogenetic analysis showed a normal karyotype 46,XY in patient 1 (P1), patient 2 (P2), and their fathers (F1 and F2). Patient 3 (P3) and his father (F3) presented a karyotype of 46,XY,Yqh-. High-throughput sequencing for the AZF disclosed an identical b2/b3 subdeletion in the F1 and F2. P1 had an AZFc deletion that accounted for 3.5 Mb, and P2 had an AZFa+b+c microdeletion that accounted for 10.5 Mb. F3 had a b2/b3 duplication of 1.8Mb, but P3 had an AZFb+c deletion of 6.2 Mb. CONCLUSIONS Our findings suggest that b2/b3 partial deletion or duplication can lead to structural instability in the Y chromosome and be a risk factor of complete deletion of AZFc or more expanded deletion during transmission.

An infertile 45,X male with a SRY-bearing chromosome 13: a clinical case report and literature review.

PURPOSE: Patients with a karyotype of 45,X (monosomy X) normally display a female phenotype. However, in some rare cases, monosomy X is associated with maleness. Here we describe a case of a male with a 45,X karyotype and primary infertility, which prompted molecular investigation of the sex-determination gene SRY. METHODS: Karyotyping was performed by GTG-banded chromosome analysis. The presence and location of SRY was investigated using PCR and FISH, respectively. RESULTS: PCR confirmed the presence of the SRY gene while FISH analysis demonstrated its location on the p arm of chromosome 13. These findings demonstrate that autosomal retention of SRY can be sub-microscopic and emphasize the importance of PCR and FISH in the genetic workup of the monosomic X male.

Placental mosaicism for Trisomy 13: a challenge in providing the cell-free fetal DNA testing.

PURPOSE: We investigated the disagreement between the positive cell-free fetal DNA test for trisomy 13 and the standard cytogenetic diagnosis of one case. METHODS: Cell-free fetal DNA testing was performed by massively parallel sequencing. We used conventional cytogenetic analysis to confirm the commercial cell-free fetal DNA testing. Additionally, postnatal fluorescent in situ hybridization (FISH) testing was performed on placental tissues. RESULTS: The cell-free fetal DNA testing result was positive for trisomy 13. G-banded analysis of amniotic fluid was normal, 46, XY. FISH testing of tissues from four quadrants of the placenta demonstrated mosaicism for trisomy 13. CONCLUSIONS: A positive cell-free fetal DNA testing result may not be representative of the fetal karyotype because of placental mosaicism. Cytogenetic analysis should be performed when abnormal cell-free fetal DNA test results are obtained.

Evaluation of elite table tennis players' technique effectiveness.

Abstract This study constructed a technique effectiveness evaluation formula for table tennis players based on the relationship between the scoring rate and usage rate of techniques and established evaluation criteria through the examination of 224 matches of the world's top 35 players. It also built a competition performance formula with the score difference theory for the exploration of the correlation between player technique effectiveness and competition performance. The results showed the three indices - the technique effectiveness of the first and third strokes (TE1,3), the second and fourth strokes (TE2,4) and the after fourth strokes (TE>4) - could help better evaluate the technique effectiveness of elite players. The comparative analysis of Chinese elite table tennis players and players from other countries and regions revealed that Chinese players as a whole were 'excellent' in all the examined techniques except in the male's 'first and third strokes'; while players from other countries and regions were overall 'general'. The case analysis of two of the world's top players further indicated that correlation analysis of technique effectiveness and competition performance could help identify the technique indices highly correlated with player competition performance.

Chromothripsis is a novel biomarker for prognosis and differentiation diagnosis of pancreatic neuroendocrine neoplasms.

This study aimed to identify the role of chromothripsis as a novel biomarker in the prognosis and differentiation diagnosis of pancreatic neuroendocrine neoplasms (pNENs). We conducted next-generation gene sequencing in a cohort of 30 patients with high-grade (G3) pNENs. As a reference, a similar analysis was also performed on 25 patients with low-grade (G1/G2) pancreatic neuroendocrine tumors (pNETs). Chromothripsis and its relationship with clinicopathological features and prognosis were investigated. The results showed that DNA damage response and repair gene alteration and TP53 mutation were found in 29 and 11 patients, respectively. A total of 14 out of 55 patients had chromothripsis involving different chromosomes. Chromothripsis had a close relationship with TP53 alteration and higher grade. In the entire cohort, chromothripsis was associated with a higher risk of distant metastasis; both chromothripsis and metastasis (ENETS Stage IV) suggested a significantly shorter overall survival (OS). Importantly, in the high-grade pNENs group, chromothripsis was the only independent prognostic indicator significantly associated with a shorter OS, other than TP53 alteration or pathological pancreatic neuroendocrine carcinomas (pNECs) diagnosis. Chromothripsis can guide worse prognosis in pNENs, and help differentiate pNECs from high-grade (G3) pNETs.

45,X mosaicism in northeast China: a clinical report and review of the literature.

PURPOSE: To explore the prevalence and clinical features, especially the reproductive function, of 45,X mosaicism patients in northeast China. METHODS: GTG-banding was performed on a series of 2,250 patients from our genetic counseling clinic. Each of these patients underwent a physical examination and was interviewed about their medical history and reproductive problems. Literature on 45,X mosaicism was accessed using PubMed and reviewed. RESULTS: The prevalence of 45,X mosaicism in northeast China is 0.36 % (8/2250), and the mosaic karyotype of our study accounted for 61.54 % (8/13) of Turner syndrome cases. This is comparable with studies from Asia, Europe, South America and other regions. The affected patients showed genital abnormalities, abnormal pregnancy or infertility. CONCLUSION: 45,X mosaicism is commonly seen in the genetic counseling clinic. Extensive cytogenetic assessment may improve the detection rate in patients with congenital dysplasia, or history of abnormal pregnancy or infertility. Karyotyping plays a key role in prognosis and assisted reproduction or early surgical treatment.

Impact of chromosomal heteromorphisms on reproductive failure and analysis of 38 heteromorphic pedigrees in Northeast China.

PURPOSE: To compare the frequency of chromosomal heteromorphisms in reproductive failure and fertile control individuals in Northeast China, and investigate the impact on reproductive failure METHODS: 1751 males and 1424 couples with reproductive failure (n = 4599) and 777 fertile control individuals in Northeast China were enrolled. Chromosome karyotype analysis was performed on peripheral blood lymphocytes with standard G-banding. Additionally, C-banding was performed with heterochromatin heteromorphisms, and NORs-banding with satellites/stalks variations. Multiplex polymerase chain reaction (PCR) adopted for the amplification using nine specific sequence tagged sites (STS) were used to detect Y-chromosome microdeletions with Y chromosome variations (Yqh±). At the same time, 38 heteromorphic probands' family members were recalled for performing karyotype analysis and to be surveyed for their detailed reproductive history. RESULTS: The frequency of chromosomal heteromorphisms in reproductive failure patients (2.74 %, 126/4599) was of no statistically significant difference as compared with fertile control individuals (2.06 %, 16/777) (P > 0.05). Eight cases of Y variation (Yqh±) probands with Y-chromosomal microdeletions were detected among 44 reproductive failure patients and 6 fertile control men. In the 38 recalled families, the probands of fathers or mothers, even some of their brothers or sisters, had the same heteromorphic karyotypes as probands' despite that they didn't have any adverse reproductive history. CONCLUSIONS: There was no statistically significant difference in frequency of chromosomal heteromorphisms between reproductive failure and fertile control individuals in Northeast China. Males with Y variations (Yqh±) should be ordered Y-chromosomal microdeletions detection. Through the analysis of 38 recalled families, we can also conclude that chromosomal heteromorphisms were not the impact factors for reproductive failure.

Evaluation of elite table tennis players' technique effectiveness.

This study constructed a technique effectiveness evaluation formula for table tennis players based on the relationship between the scoring rate and usage rate of techniques and established the evaluation criteria through the examination of 224 matches of the world's top 35 players. It also built a competition performance formula with the score difference theory for the exploration of the correlation between player technique effectiveness and competition performance. The results showed the three indices--the technique effectiveness of the first and third strokes (TE1,3), the second and fourth strokes (TE2,4) and the after fourth strokes (TE(>4))--could help better evaluate the technique effectiveness of elite players. The comparative analysis of Chinese elite table tennis players and players from other countries and regions revealed that Chinese players as a whole were "excellent" in all the examined techniques except in the male's "first and third strokes"; while players from other countries and regions were overall "general". The case analysis of two world top players further indicated that correlation analysis of technique effectiveness and competition performance could help identify the technique indices highly correlated with player competition performance.

[Clinical and cytogenetic analysis of 45,X/46,XY individuals].

OBJECTIVE: To analyze main clinical manifestations and cytogenetic characteristics of patients with a 45,X/46,XY karyotype. METHODS: G-banding karyotype analysis was carried out. PCR was performed to detect azoospermia factor (AZF) microdeletion in adult male patients and sex-determining region on Y chromosome (SRY) gene in all patients. Clinical phenotype and genetic characteristics were summarized. RESULTS: Among the 9 individuals with 45,X/46,XY, there have been 7 males and 2 females. Six out of the 7 males have manifested primary infertility, which included 5 with azoospermia, 1 with oligospermia, and 1 with hypospadia. Three of the 6 infertile patients were found to have AZF microdeletions. Two females showed typical Turner syndrome. All of the 9 cases were SRY-positive. CONCLUSION: The 45,X/46,XY karyotype may result in a range of phenotypes. No correlation has been found between clinical manifestations and proportion of mosaicism cells for their peripheral blood karyotypes. As phenotypically normal male patients may produce sperm, infertile patients should undergo further examination at the molecular level.

[Molecular genetic mechanisms of teratozoospermia].

Teratozoospermia is one of the important factors contributing to male infertility, and its pathogenesis is not yet clear. Recent years have witnessed some progress in the researches on sperm morphology, and some genes have been confirmed to be correlated with spermatogenesis. Aiming to provide some evidence for the pathogenesis of teratozoospermia, this paper reviews the relevant literature in the past five years addressing such special teratozoospermia as globozoospermia, nuclear vacuoles, decapitated spermatozoa, excessive residual cytoplasm, dysplasia of the fibrous sheath, and primary ciliary dyskinesia, and elaborates on the molecular genetic mechanisms of DPY19L2, AR, PRM1, GBA2, PCI, CREM, TH2A, TH2B, ODF1, Cntrob, OAZ-t, HOOK1, SPEM1, GAT1, PRSS21, 15-LOX, Sptrx, AKAP3, AKAP4, DNAI1, DNAH5, RSPH4A, TXNDC3, CCDC39, LRRC6, LRRC50, KTU and so on. Meanwhile, this review also presents an overview on the latest advances in assisted reproductive technology and its outcomes in the treatment of teratozoospermia patients in order to provide a theoretical basis for the diagnosis and treatment of male infertility.

Associations of sex hormone levels with body mass index (BMI) in men: a cross-sectional study using quantile regression analysis.

Body mass index (BMI) has been increasing globally in recent decades. Previous studies reported that BMI was associated with sex hormone levels, but the results were generated via linear regression or logistic regression, which would lose part of information. Quantile regression analysis can maximize the use of variable information. Our study compared the associations among different regression models. The participants were recruited from the Center of Reproductive Medicine, The First Hospital of Jilin University (Changchun, China) between June 2018 and June 2019. We used linear, logistic, and quantile regression models to calculate the associations between sex hormone levels and BMI. In total, 448 men were included in this study. The average BMI was 25.7 (standard deviation [s.d.]: 3.7) kg m-2; 29.7% (n = 133) of the participants were normal weight, 45.3% (n = 203) of the participants were overweight, and 23.4% (n = 105) of the participants were obese. The levels of testosterone and estradiol significantly differed among BMI groups (all P < 0.05). In linear regression and logistic regression, BMI was associated with testosterone and estradiol levels (both P < 0.05). In quantile regression, BMI was negatively associated with testosterone levels in all quantiles after adjustment for age (all P < 0.05). BMI was positively associated with estradiol levels in most quantiles (≤80th) after adjustment for age (all P < 0.05). Our study suggested that BMI was one of the influencing factors of testosterone and estradiol. Of note, the quantile regression showed that BMI was associated with estradiol only up to the 80th percentile of estradiol.

Male infertility in Northeast China: a cytogenetic study of 135 patients with non-obstructive azoospermia and severe oligozoospermia.

PURPOSES: To detect the frequency and types of chromosomal anomalies with non-obstructive azoospermia and severe oligozoospermia in Northeast China, and to compare the frequencies with other regions of China and the world. To investigate the general characteristics of this population. METHODS: Eighty-one men with non-obstructive azoospermia and 54 men with severe oligozoospermia were recruited. Karyotype analyses were performed on peripheral blood lymphocytes using standard G-banding. Measurements of follicle-stimulating hormone, testosterone, prolactin, and inhibin B were obtained. RESULTS: The frequency of chromosomal anomalies for patients with non-obstructive azoospermia (17.28%) was comparable with studies from Europe, Africa, Asia, and other regions of China. However, the frequency for patients with severe oligozoospermia (9.26%) was slightly higher than reported from other Asian countries. The infertile men were more likely than the fertile to smoke and consume alcohol, and to have significantly lower levels of inhibin B. CONCLUSIONS: For infertile men in Northeast China, chromosome analysis is a necessary part of routine genetic testing, and the contributing effects of high smoking and alcohol consumption rates of this population should be discussed during genetic counseling.

[AZF deletions and male infertility].

The Y chromosome contains genes closely related to male gonadal development and spermatogenesis. The azoospermia factor (AZF) is a gene on the long arm of the Y chromosome that regulates spermatogenesis, and its deletion can induce spermatogenic arrest and consequently male infertility. Most researchers subdivide AZF into AZFa, AZFb and AZFc, and some believe there to be another region, AZFd, between AZFa and AZFb. Different AZF deletions lead to different phenotypes. AZFc deletion, as the commonest type that attracts widespread attention of researchers, includes complete AZF deletion and partial AZF deletion, and the latter mainly consists of gr/gr deletion and b2/b3 deletion. The gr/gr deletion can cause infertility in some areas or in human species. The influence of b2/b3 deletion on spermatogenesis has not been confirmed, but its wide spread in haplogroup N has distribution scientists' attention. This review outlines the structures, candidate genes and deletions of AZF, especially AZFc, along with their relationship with spermatogenesis, so as to provide a theoretical basis for clinical prenatal diagnosis and treatment of infertility.

[Y chromosome microdeletions in severe oligospermia men with varicocele].

OBJECTIVE: To investigate Y chromosome microdeletions in severe oligospermia men with varicocele. METHODS: We randomly selected 100 cases of severe oligospermia with left varicocele (sperm concentration <5 x 10(6)/ml, group 1), 100 cases of mild oligospermia with left varicocele (sperm concentration 10 -20 x 10(6)/ml, group 2), 100 cases of idiopathic infertility with severe oligospermia (group 3), 100 cases of idiopathic infertility with moderate oligospermia (group 4) and 30 normal fertile men as controls (group 5). We used polymerase chain reaction (PCR) technology to screen 9 sequence tagged sites (STS) of the AZF a, b and c regions and detect Y chromosome microdeletions. RESULTS: AZF microdeletions were found in 19 patients in group 1 (19%) and 11 in group 3 (11%), with a higher rate in the former than in the latter, but not in the other three groups. CONCLUSION: Screening of Y chromosome microdeletions should be performed before the treatment of severe spermatogenesis with varicocele.

Molecular cytogenetic characterization of 2q deletion and Xq duplication associated with nasal bone dysplasia in prenatal diagnosis: A case report and literature review.

OBJECTIVE: We report a prenatal case of male fetus with a 2q13 deletion and an Xq27.3q28 duplication, presenting nasal bone dysplasia by ultrasound examination. And we compare the similarities of clinical features of cases consisting of similar 2q deletion and Xq duplication. CASE REPORT: A 30-year-old woman was referred for prenatal diagnosis and genetic counseling at 24 weeks of gestation. Prenatal ultrasound showed nasal bone dysplasia of the fetus. Amniocentesis revealed the karyotype of the fetus as 46, XY and the results of chromosomal microarray analysis was arr[GRCh37] 2q13(110467258-111370025)x1, arr[GRCh37]Xq27.3q28(144050780-149748782)x2. The parents both have normal karyotypes. The couple chose to continue the pregnancy and finally delivered a male infant at 39 weeks of gestation. His weight was 2850 g and length was 50 cm. Physical examination of the newborn revealed no apparent anomalies. Until the boy was one year old, there was no abnormalities in his growth and development. The long-term follow-up till adulthood for the healthy infant is necessary. CONCLUSION: The development of CMA plays a critical role in prenatal diagnosis and genetic counseling for unidentified chromosomal anomalies. More clinical information and further studies of patients with these anomalies will identify the pathogenicity of the involving genes and improve the understanding of the phenotype-genotype correlation.

Immune-Related Pneumonitis Was Decreased by Addition of Chemotherapy with PD-1/L1 Inhibitors: Systematic Review and Network Meta-Analysis of Randomized Controlled Trials (RCTs).

PURPOSE: Immune-related pneumonitis (IRP) has attracted extensive attention, owing to its increased mortality rate. Conventional chemotherapy (C) has been considered as an immunosuppressive agent and may thus reduce IRP's risk when used in combination with PD-1/L1 inhibitors. This study aimed to assess the risk of IRP with PD-1/L1 inhibitors plus chemotherapy (I+C) versus PD-1/L1 inhibitors alone (I) in solid cancer treatment. METHOD: Multiple databases were searched for RCTs before January 2021. This NMA was performed among I+C, I, and C to investigate IRP's risk. Subgroup analysis was carried out on the basis of different PD-1/L1 inhibitors and cancer types. RESULTS: Thirty-one RCTs (19,624 patients) were included. The I+C group exhibited a lower risk of IRP in any grade (RR, 0.60; 95% CI, 0.38-0.95) and in grade 3-5 (RR, 0.44; 95% CI, 0.21-0.92) as opposed to the I group. The risk of any grade IRP with PD-1 plus chemotherapy was lower than that with PD-1 monotherapy (RR, 0.50; 95% CI, 0.28-0.89), although grade 3-5 IRP was similar. There was no statistically meaningful difference in the risk of any grade IRP between PD-L1 plus chemotherapy and PD-L1 inhibitors monotherapy (RR, 0.95; 95% CI, 0.43-2.09) or grade 3-5 IRP (RR, 0.71;95% CI, 0.24-2.07). In addition, compared with the I group, the I+C group was correlated with a decreased risk in IRP regardless of cancer type, while a substantial difference was only observed in NSCLC patients for grade 3-5 IRP (RR, 0.39; 95% CI, 0.15-0.98). CONCLUSION: In comparison to PD-1/L1 inhibitor treatment alone, combining chemotherapy with PD-1/L1 inhibitors might reduce the risk of IRP in the general population. Furthermore, PD-1 inhibitors in combination with chemotherapy were correlated with a decreased risk of IRP compared to PD-1 inhibitor treatment alone. In contrast to the I group, the I+C group exhibited a lower risk of IRP, especially for NSCLC patients.

Efficacy and safety of raltitrexed plus S-1 versus regorafenib in patients with refractory metastatic colorectal cancer: a real-world propensity score matching study.

Background: Raltitrexed plus S-1 (RS) and regorafenib both showed considerable efficacy for metastatic colorectal cancer (mCRC) patients. This study aims to compare the effectiveness and safety of two different regimens in patients with refractory mCRC. Methods: This retrospective cohort study included mCRC patients who were treated with RS or regorafenib from February 2017 to June 2021. A propensity score matching (PSM) analysis was conducted to balance the baseline characteristics of all patients. Progression-free survival (PFS), overall survival (OS), tumor response, and safety of two regimens were evaluated. Results: A total of 187 patients were included in our study, with 107 patients in the RS group and 80 patients in the regorafenib group. After PSM, 78 pairs were recognized. Patients treated with RS had a semblable PFS compared to those treated with regorafenib before PSM (4.8 months vs 5.5 months, p = 0.400) and after PSM (4.7 months vs 5.4 months, p = 0.430). Patients in the RS group were associated with a longer OS than those in the regorafenib group (13.4 months vs 10.1 months, p = 0.010). A similar trend of OS was also obtained in the matched cohort (13.3 months vs 10.0 months, p = 0.024). Both objective response rate (12.8% vs 5.1%, p = 0.093) and disease control rate (53.8% vs 46.2%, p = 0.337) in the RS cohort were higher than those in the regorafenib group, without significant differences. Adverse events (AEs) of each group were well tolerated. Conclusion: Patients treated with RS demonstrated a longer OS than those treated with regorafenib and had manageable AEs, which could be recognized as a primary choice for refractory mCRC. Plain Language Summary: Efficacy and Safety of Raltitrexed plus S-1 Versus Regorafenib in Patients with Refractory Metastatic Colorectal Cancer: A Real-world Propensity Score Matching StudyBoth raltitrexed plus S-1 (RS) and regorafenib showed considerable efficacy for metastatic colorectal cancer (mCRC) patients. No study has compared the two regimens yet. Therefore, we compare the efficacy and safety between RS and regorafenib to provide an optimal treatment option. We retrospectively included patients with mCRC who failed at least two standard treatments. All enrolled patients received RS or regorafenib treatments. We conducted a propensity score matching to eliminate differences in the enrolled patients. After the analysis, we found no significant differences in progression-free survival in patients between the two groups. However, patients treated with RS had a longer OS than those treated with regorafenib, whether before matching (13.4 months vs 10.1 months, p = 0.010) or after matching (13.3 months vs 10.0 months, p = 0.024). In addition, the adverse effects caused by cancer-related therapy were tolerable for the patient. Certainly, this is a non-randomized retrospective study with a small sample size, so we conducted a propensity score matching to minimize potential bias. Importantly, this is the first research comparing the two treatments, and we believe that the results of this article could present a primary choice for clinical doctors dealing with patients with standard treatments that failed mCRC.