Engineering of g-C3N4 for Photocatalytic Hydrogen Production: A Review.

Graphitic carbon nitride (g-C3N4)-based photocatalysts have garnered significant interest as a promising photocatalyst for hydrogen generation under visible light, to address energy and environmental challenges owing to their favorable electronic structure, affordability, and stability. In spite of that, issues such as high charge carrier recombination rates and low quantum efficiency impede its broader application. To overcome these limitations, structural and morphological modification of the g-C3N4-based photocatalysts is a novel frontline to improve the photocatalytic performance. Therefore, we briefly summarize the current preparation methods of g-C3N4. Importantly, this review highlights recent advancements in crafting high-performance g-C3N4-based photocatalysts, focusing on strategies like elemental doping, nanostructure design, bandgap engineering, and heterostructure construction. Notably, sophisticated doping techniques have propelled hydrogen production rates to a 104-fold increase. Ingenious nanostructure designs have expanded the surface area by a factor of 26, concurrently extending the fluorescence lifetime of charge carriers by 50%. Moreover, the strategic assembly of heterojunctions has not only elevated charge carrier separation efficiency but also preserved formidable redox properties, culminating in a dramatic hundredfold surge in hydrogen generation performance. This work provides a reliable and brief overview of the controlled modification engineering of g-C3N4-based photocatalyst systems, paving the way for more efficient hydrogen production.

Unmasking the silent killer: The hidden aggressiveness of signet-ring cell carcinoma in gallbladder cancer.

The prognostic significance of the signet-ring cell component in gallbladder carcinoma (GBC) has not been systematically evaluated. The aim of this study was to assess the similarities and differences between gallbladder signet-ring cell carcinoma (GBSRCA) and gallbladder adenocarcinoma (GBAC) in terms of clinicopathological features and long-term survival. Using the Surveillance, Epidemiology, and End Results (SEER) database, we analyzed 6,612 patients diagnosed with gallbladder cancer between 2000 and 2021. The cohort included 147 patients with GBSRCA and 6,465 with GBAC. Patients with GBSRCA were significantly younger, with 33.3% being age 60 or younger compared to 23.9% of patients with GBAC (p = 0.009). There was a higher proportion of females in the GBSRCA group (77.6%) compared to the GBAC group (70.1%, p = 0.049). GBSRCA was associated with a more advanced tumor stage (T3-T4: 56.5% vs. 44.4%, P = 0.004), higher rates of lymph node metastasis (43.5% vs. 28.0%, P < 0.001), and poorer differentiation status (poorly to undifferentiated: 80.3% vs. 29.7%, P < 0.001). Survival analysis revealed that patients with GBSRCA had significantly worse overall survival (OS) and cancer-specific survival (CSS) compared to patients with GBAC (p < 0.001). GBSRCA was an independent prognostic factor for OS (P = 0.001) in the entire cohort, while the T stage and N stage were independent prognostic factors for OS and CSS in patients with GBSRCA. Even after propensity score matching, patients with GBSRCA still had a poorer prognosis.

Unveiling the unexplored secret: Aggressive behavior and poor survival in intrahepatic mucinous adenocarcinoma compared to conventional adenocarcinoma.

Intrahepatic bile duct mucinous adenocarcinoma (IHBDMAC) is a rare pathological subtype of intrahepatic cholangiocarcinoma (IHCC), and its tumor biological features and survival outcomes have rarely been explored, especially when compared to the most common subtype, intrahepatic bile duct adenocarcinoma (IHBDAC). Therefore, the aim of this study was to explore the clinical features and survival outcomes of IHBDAC and IHBDMAC using the Surveillance, Epidemiology, and End Results (SEER) database from 2000 to 2021. A total of 1,126 patients were included, with 1,083 diagnosed with IHBDAC and 43 diagnosed with IHBDMAC. Patients with IHBDMAC presented with a more advanced T stage (55.8% vs. 36.9%, P = 0.012) and higher rate of lymph node metastasis (37.2% vs. 24.9%, P = 0.070). Cox regression identified advanced T stage, lymph node metastasis, and distant metastasis as poor survival predictors, while chemotherapy and surgery were protective factors. Survival analyses revealed significantly worse overall survival (OS) and cancer-specific survival (CSS) for IHBDMAC compared to IHBDAC (P < 0.05). Even after matching, patients with IHBDMAC still had a worse prognosis than those with IHBDAC. These findings highlight the aggressive nature of IHBDMAC and the need for tailored therapeutic strategies. Future research should focus on prospective studies and molecular insights to develop targeted treatments for IHBDMAC.

Low-frequency RTMS attenuates social impairment in the VPA-induced mouse model.

BACKGROUND: Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by impaired social interactions and repetitive behaviors. Despite its prevalence, effective treatments remain elusive. Recent studies have highlighted the importance of the balance between GABAergic and glutamatergic neuronal synaptic functions in ASD development. Repetitive transcranial magnetic stimulation (RTMS) is a painless and effective treatment allowed for use in depression and obsessive-compulsive disorder. However, its efficacy in treating autism is still under investigation. Low-frequency RTMS (LF-RTMS), which shows promise in reducing autism-like behaviors, is considered to regulate synaptic function. OBJECTIVE: We observed and recorded the behaviors of mice to assess the impact of RTMS on their social interactions and repetitive activities. Subsequently, we examined GABAergic and glutamatergic neuronal markers along with synaptic marker proteins to understand the underlying changes associated with these behaviors. METHODS: To evaluate behaviors associated with autism spectrum disorder (ASD), several behavioral tests were conducted, focusing on sociability, repetitive behaviors, locomotion, anxiety, and depression. Additionally, Western blot and immunofluorescence staining were employed to investigate the activity of GABAergic and glutamatergic neurons in the hippocampus, aiming to understand the synaptic mechanisms underlying these behaviors. RESULTS: LF-RTMS treatment effectively relieved the social disability and normalized synaptic function in the hippocampus of ASD mice model induced by valproate (VPA). Importantly, this treatment did not lead to any adverse effects on repetitive behavior, locomotion, anxiety, or depression. CONCLUSION: LF-RTMS attenuated social disability without affecting repetitive behavior, locomotion, anxiety, or depression. Changes in the expression of GABAergic and glutamatergic neuronal synaptic proteins in the hippocampus were also observed.

Optimizing the Heat Treatment Method to Improve the Aging Response of Al-Fe-Ni-Sc-Zr Alloys.

This work has studied the co-addition of Sc and Zr elements into the Al-1.75wt%Fe-1.25wt%Ni eutectic alloy. The changes in the microstructure, electrical conductivity, and Vickers hardness of the Al-1.75wt%Fe-1.25wt%Ni-0.2wt%Sc-0.2wt%Zr alloy during heat treatment were studied. The results showed that two-step aging can effectively improve the aging response of the alloy over the single-step aging method. This was ascribed to the minimization of the diffusion difference between Sc and Zr elements. Furthermore, the homogenization treatment can also improve the aging response of the alloy by alleviating the uneven distribution of Sc and Zr. Nevertheless, the micro-alloyed elements exceeded the solid solubility limit in the Al-1.75wt%Fe-1.25wt%Ni-0.2wt%Sc-0.2wt%Zr alloy, and their strengthening effect has ever achieved the best prospect. Finally, both Sc and Zr contents were reduced simultaneously, and the aging response of the Al-1.75wt%Fe-1.25wt%Ni-0.15wt%Sc-0.1wt%Zr alloy was improved by optimized heat treatment. The underlying mechanisms for this alloy design and the corresponding microstructure-mechanical property relationship were analytically discussed.

The prognostic nutritional index and tumor pathological characteristics predict the prognosis of elderly patients with early-stage hepatocellular carcinoma after surgery.

The elderly comprises over one-third of hepatocellular carcinoma (HCC) patients, however, they are not adequately represented in prognostic studies. The study aims to determine the prognostic significance of the preoperative prognostic nutritional index (PNI) and develop nomograms for predicting their recurrence-free and overall survival (RFS and OS). The study consisted of 282 elderly patients (aged ≥ 65 years) with early-stage HCC (China Liver Cancer Staging System: I-IIA) after curative resection (R0). They were randomly divided into a training (n = 197) and a test cohort (n = 85). The patients were stratified into two groups: PNI-low (PNI ≤ 49.05) and PNI-high (PNI > 49.05) based on a cut-off value. Most patients' demographics and perioperative outcomes were comparable, while patients in the PNI-high group were younger (P = 0.002), heavier (P < 0.001), and had lower comorbidity rates (P = 0.003). Although the tumor stages were earlier in the PNI-low group (P < 0.001), patients' OS (5-year OS: 48.9% vs. 93.1%) and RFS (5-year RFS: 27.3% vs. 75.7%) were significantly worse compared to the PNI-high group (both P < 0.0001). Patients' OS and RFS nomograms were developed by incorporating independent survival predictors including chronic obstructive pulmonary disease (COPD), age ≥ 75 years, PNI-low, tumor presence of satellite nodules, capsule, and microvascular invasion. The nomograms showed good calibration and discrimination, with all C-indexes ≥ 0.75 and calibration plots essentially coinciding with the diagonal. In conclusion, for elderly HCC patients, COPD, age ≥ 75 years, PNI-low, and tumor presence of satellite nodules, capsule, and microvascular invasion were independent prognostic factors. The nomogram could accurately predict the prognosis of these patients.

Fabrication of 3D printed PCL/PEG artificial bile ducts as supportive scaffolds to promote regeneration of extrahepatic bile ducts in a canine biliary defect model.

In this study, a 3D porous poly(ε-caprolactone)/polyethylene glycol (PCL/PEG) composite artificial tubular bile duct was fabricated for extrahepatic bile duct regeneration. PCL/PEG composite scaffolds were fabricated by 3D printing, and the molecular structure, mechanical properties, thermal properties, morphology, and in vitro biocompatibility were characterized for further application as artificial bile ducts. A bile duct defect model was established in beagle dogs for in vivo implantation. The results demonstrated that the implanted PE1 ABD, serving as a supportive scaffold, effectively stimulated the regeneration of a new bile duct comprising CK19-positive and CK7-positive epithelial cells within 30 days. Remarkably, after 8 months, the newly formed bile duct exhibited an epithelial layer resembling the normal structure. Furthermore, the study revealed collagen deposition, biliary muscular formation, and the involvement of microvessels and fibroblasts in the regenerative process. In contrast, the anastomotic area without ABD implantation displayed only partial restoration of the epithelial layer, accompanied by fibroblast proliferation and subsequent bile duct fibrosis. These findings underscore the limited inherent repair capacity of the bile duct and underscore the beneficial role of the PE1 ABD artificial tubular bile duct in promoting biliary regeneration.

Risk factors for recurrent common bile duct stones: a systematic review and meta-analysis.

BACKGROUND: Common bile duct stones (CBDS) have a reported recurrence rate of 4%-24% after stone extraction. The most commonly applied stone extraction method is endoscopic cholangiopancreatography (ERCP). We conducted a systematic review and meta-analysis to identify all available risk factors for recurrent CBDS following stone retraction. RESEARCH DESIGN AND METHODS: A literature search of studies with case-control design was performed to identify potential risk factors for recurrent CBDS. The impact of different risk factors on stone recurrence was analyzed. Pooled odds ratios (ORs) with 95% CIs and heterogeneity were calculated. Identified risk factors were graded as 'strong,' 'moderate,' or 'weak' after quality assessment. RESULTS: A total of 46 studies discussing stone recurrence following ERCP treatment were included. CBD diameter≥1.5 cm, sharp CBD angulation, multiple ERCP sessions, postoperative pneumobilia, history of CBD incision, and biliary stent placement were identified as strong risk factors; larger CBD diameter, periampullary diverticulum, mechanical lithotripsy, and history of cholecystectomy were identified as moderate. Other weak risk factors were also listed. CONCLUSIONS: In this comprehensive study, we identified 14 risk/protective factors for recurrent CBDS following ERCP. Pooled odds ratios were calculated and evaluated the quality of evidence. These findings may shed light on the assessment and management of CBDS.

Vaccine adjuvants: mechanisms and platforms.

Adjuvants are indispensable components of vaccines. Despite being widely used in vaccines, their action mechanisms are not yet clear. With a greater understanding of the mechanisms by which the innate immune response controls the antigen-specific response, the adjuvants' action mechanisms are beginning to be elucidated. Adjuvants can be categorized as immunostimulants and delivery systems. Immunostimulants are danger signal molecules that lead to the maturation and activation of antigen-presenting cells (APCs) by targeting Toll-like receptors (TLRs) and other pattern recognition receptors (PRRs) to promote the production of antigen signals and co-stimulatory signals, which in turn enhance the adaptive immune responses. On the other hand, delivery systems are carrier materials that facilitate antigen presentation by prolonging the bioavailability of the loaded antigens, as well as targeting antigens to lymph nodes or APCs. The adjuvants' action mechanisms are systematically summarized at the beginning of this review. This is followed by an introduction of the mechanisms, properties, and progress of classical vaccine adjuvants. Furthermore, since some of the adjuvants under investigation exhibit greater immune activation potency than classical adjuvants, which could compensate for the deficiencies of classical adjuvants, a summary of the adjuvant platforms under investigation is subsequently presented. Notably, we highlight the different action mechanisms and immunological properties of these adjuvant platforms, which will provide a wide range of options for the rational design of different vaccines. On this basis, this review points out the development prospects of vaccine adjuvants and the problems that should be paid attention to in the future.

Improvement of transpiration estimation based on a two-leaf conductance-photosynthesis model with seasonal parameters for temperate deciduous forests.

Introduction: Conductance-photosynthesis (Gs-A) models, accompanying with light use efficiency (LUE) models for calculating carbon assimilation, are widely used for estimating canopy stomatal conductance (Gs) and transpiration (Tc) under the two-leaf (TL) scheme. However, the key parameters of photosynthetic rate sensitivity (gsu and gsh) and maximum LUE (ϵmsu and ϵmsh) are typically set to temporally constant values for sunlit and shaded leaves, respectively. This may result in Tc estimation errors, as it contradicts field observations. Methods: In this study, the measured flux data from three temperate deciduous broadleaved forests (DBF) FLUXNET sites were adopted, and the key parameters of LUE and Ball-Berry models for sunlit and shaded leaves were calibrated within the entire growing season and each season, respectively. Then, the estimations of gross primary production (GPP) and Tc were compared between the two schemes of parameterization: (1) entire growing season-based fixed parameters (EGS) and (2) season-specific dynamic parameters (SEA). Results: Our results show a cyclical variability of ϵmsu across the sites, with the highest value during the summer and the lowest during the spring. A similar pattern was found for gsu and gsh, which showed a decrease in summer and a slight increase in both spring and autumn. Furthermore, the SEA model (i.e., the dynamic parameterization) better simulated GPP, with a reduction in root mean square error (RMSE) of about 8.0 ± 1.1% and an improvement in correlation coefficient (r) of 3.7 ± 1.5%, relative to the EGS model. Meanwhile, the SEA scheme reduced Tc simulation errors in terms of RMSE by 3.7 ± 4.4%. Discussion: These findings provide a greater understanding of the seasonality of plant functional traits, and help to improve simulations of seasonal carbon and water fluxes in temperate forests.

Comparison of current guidelines and consensus on the management of patients with cholangiocarcinoma: 2022 update.

As a consequence of breakthroughs in the area of guidelines research, the therapy for cholangiocarcinoma has significantly improved the efficacy rate of diagnosis and survival outcomes. We compared the most recently updated clinical practice guidelines and consensus to provide recommendations based on the diagnostic and therapeutic equipment available in various countries. Following a systematic review, we discovered that these guidelines and consensus had both similarities and differences in terms of what organizations or groups drafted the guidelines and the approach, applicability, content and recent updates of the guidelines as well as in terms of diagnostic and treatment algorithms. The disparities could be attributable to a variety of etiological factors, high risk patients, health resources, medical technology, treatment options, and income levels. Additionally, while complete adoption of guidelines may benefit physicians, patients, and authorities, there remains a disconnect between expected goals and implementation.

The clinical management of hepatocellular carcinoma worldwide: A concise review and comparison of current guidelines: 2022 update.

Hepatocellular carcinoma (HCC) is the fifth most common malignancy and the second leading cause of cancer-related mortality worldwide. This review is an updated version that summarizes comprehensive guidelines published from January 2001 to January 2022 worldwide with a focus on the clinical management of HCC. The electronic databases MEDLINE, the Chinese SinoMed, and the Japanese CiNii were systematically searched. A total of 22 characteristic guidelines for HCC management were ultimately included, including 1 international guideline, 11 guidelines from Asia, 5 from Europe, 4 from the America, and 1 from Australia. If guidelines were published in multiple versions, the most recent update was included, and surveillance, diagnosis, and treatment were compared. The composition of and recommendations in current guidelines on HCC varied, so these guidelines were regrouped and diagnostic and treatment algorithms were summarized graphically to provide the latest information to clinicians. The diagnostic criteria were grouped into 2 categories: a "Size-based pathway" and a "Non-size-based pathway". The treatment criteria were summarized according to different treatment algorithms, and mainstream treatment options were reviewed. Findings from comparison of current guidelines might help target and concentrate efforts to improve the clinical management of HCC. However, further studies are needed to improve the management and outcomes of HCC. More straightforward or refined guidelines would help guide doctors to make better decisions in the treatment of HCC in the future.

Prediction of Early Recurrence After R0 Resection for Gallbladder Carcinoma of Stage T1b-T3.

PURPOSE: The time-to-tumor recurrence can predict the prognosis of hepatobiliary cancers following curative-intent resection. Therefore, for patients with gallbladder carcinoma (GBC) of stage T1b-T3 who had undergone R0 resection, we investigated the risk factors for early recurrence of GBC and their prognosis. PATIENTS AND METHODS: A total of 260 patients with GBC with T1b-T3 disease and an R0 margin were identified. Their clinicopathologic characteristics, perioperative details and prognostic data were reviewed. Survival analyses were carried out using the Kaplan-Meier method. Logistic regression models were used to identify the risk factors for early recurrence. RESULTS: The optimal cutoff for early recurrence was 29 months. Early recurrence tended to result in relapse far from the primary tumor, and such patients tended to have significantly worse overall survival. Multivariate analysis revealed that T3 disease, N1/N2 stage, poor differentiation of tumor, and lymphovascular invasion (LI) were associated with a greater risk of early recurrence. Patients diagnosed as having GBC incidentally and who had the risk factors of early recurrence were more likely to benefit from re-resection 2-4 weeks after a cholecystectomy. CONCLUSION: T3 stage, N1-N2 stage, poor differentiation, and LI were independent risk factors associated with early recurrence for patients with GBC with stage T1b-T3 disease after R0 resection.

Diagnostic Accuracy of Serum/Plasma Circular RNAs and the Combination of Circular RNAs and α-Fetoprotein for Detecting Hepatocellular Carcinoma: A Meta-Analysis.

The lack of an accurate biomarker in hepatocellular carcinoma (HCC) has hindered early detection, diagnosis, and treatment. Circular RNAs (circRNAs), which can be used as novel biomarkers in liquid biopsies, have been brought to light as a result of the advances in research on molecular biomarkers and the progression of genomic medicine. We conducted a meta-analysis of the diagnostic accuracy of serum/plasma circRNAs or the combination of circRNAs and α-fetoprotein (AFP) in HCC. We identified eight studies that met the inclusion/exclusion criteria from PubMed, Web of Science, EMBASE, and Cochrane Library databases. The data were pooled, and the sensitivity, specificity, diagnostic odds ratio (DOR), positive likelihood ratio (+LR), and negative likelihood ratio (-LR) with 95% confidence intervals (CIs) were calculated. The areas under the summary receiver operator characteristic (SROC) curves (AUCs) were also calculated. The sensitivity of circRNAs was 0.82 (95% CI: 0.78-0.85), and the specificity was 0.82 (95% CI: 0.78-0.86). The sensitivity of AFP was 0.65 (95% CI: 0.61-0.68), and the specificity was 0.90 (95% CI: 0.85-0.93). The AUC was 0.89 (95% CI: 0.86-0.91) for circRNAs and 0.77 (95% CI: 0.74-0.81) for AFP. The sensitivity of the combination of circRNAs and AFP was 0.88 (95% CI: 0.84-0.92), specificity was 0.86 (95% CI: 0.80-0.91), and AUC was 0.94 (95% CI: 0.91-0.96). Additionally, a subgroup analysis was conducted based on the control groups used; the diagnostic accuracy was particularly high in the comparison of HCC vs. healthy controls. In summary, serum/plasma circRNAs are accurate biomarkers suitable for clinical use for detecting HCC, and the combination of circRNAs and AFP improved the diagnostic accuracy.

Mixed adenoneuroendocrine carcinomas of stomach and ampulla of vater after curative-intent resection: a single center cases series.

BACKGROUND: Mixed adenoneuroendocrine carcinoma is a rare clinical manifestation, especially in the gastric and ampullary. The purpose of this study was to investigate the clinicopathological features and prognosis of mixed adenoneuroendocrine carcinoma in the gastric and ampullary and summarize related treatment suggestions. METHODS: In all, 32 cases of mixed adenoneuroendocrine carcinoma in the gastric and ampullary that were diagnosed from resected specimens were analyzed from 2009 to 2015. The corresponding demographic, clinicopathological and survival data were retrospectively reviewed. RESULTS: The 1-year, 3-year and 5-year survival rates were 78.1%, 28.1 and 9.4%, respectively, and the median overall survival was 28.0 months. In all, 75.0% (24/32) had lymph node metastasis at the time of initial diagnosis. A multivariate analysis revealed that TNM stage (HR 6.444 95%CI 1.477-28.121 P = 0.013), lymph nodes metastasis (HR10.617 95%CI 1.409-79.997 P = 0.022), vascular invasion (HR 5.855 95%CI 1.719-19.940 P = 0.005), grade of the adenocarcinoma component (HR 3.876 95%CI 1.451-10.357 P = 0.007) and CD56 positivity (HR 0.265 95%CI 0.100-0.705 P = 0.008) were independent predictors of overall survival. CONCLUSIONS: Mixed adenoneuroendocrine carcinoma is an aggressive clinical entity with a poor prognosis. Taking both the neuroendocrine component and the adenocarcinoma component into consideration of optimal treatment is strongly recommended.

Postsurgical radiotherapy in stage IIIB gallbladder cancer patients with one to three lymph nodes metastases: A propensity score matching analysis.

BACKGROUND: The effect of postsurgical radiotherapy (PSRT) among T1-3 gallbladder cancer (GBC) patients with one to three lymph node metastases remains controversial. The aim of this study was to assess the impact of PSRT on gallbladder cancer-specific survival (GBCSS) in patients with stage IIIB. METHODS: The data of GBC patients were obtained from the American Surveillance, Epidemiology, and End Results (SEER) Data resources between 2004 and 2015. Then, a 1:1 propensity score matching (PSM) method was performed. GBCSS was compared among all patients. Subgroup analysis was conducted to identify patients who would benefit from PSRT. RESULTS: 726 AJCC (8th edition) stage IIIB GBC patients were included. PSRT failed to improve GBCSS (p = 0.168). Male sex, tumor size ≥ 4 cm and absence of chemotherapy were independent negative prognostic factors. No significant survival benefit from PSRT was found in any subgroup. CONCLUSIONS: PSRT provides no survival benefit for IIIB GBC.

Laparoscopic appendectomy is safe and feasible in pregnant women during second trimester: A retrospective study in a top-level Chinese center.

Acute appendicitis (AA) is the most common nonobstetric surgical emergency during pregnancy. According to the current guidelines and meta-analyses, traditional open appendectomy (OA) is still recommended for pregnant patients over laparoscopic appendectomy (LA), which might be associated with higher rates of fetal loss. Previous studies and experiences indicated that LA might be safe in the second trimester of pregnancy. The current study aimed to evaluate the safety and feasibility of LA in pregnant women during the second trimester.At our institution, a retrospective study was conducted with pregnant patients who underwent LA or OA during the second trimester between January 2016 and August 2018.A total of 48 patients were enrolled. Of them, 12 were managed with laparoscopy and 36 with the open approach. We found that the LA group had higher BMIs than the OA group (4.0 ±â€Š4.3 vs 21.5 ±â€Š2.9, P = .031). The financial results showed that the average daily medical costs for patients who underwent LA was higher than those who underwent OA (444 ±â€Š107 US$ vs 340 ±â€Š115 US$, P = .009), while the total cost of hospitalization was comparable between the 2 approaches. The perioperative and obstetric outcomes were comparable between LA and OA. In each group, only 1 patient had fetal loss. No "Yinao" was found in any of the patients in the LA group.In this study, with the proven advantages of the laparoscopic techniques, LA was found to be safe and feasible for pregnant women during the second trimester.

A Novel Nomogram Predicting Distant Metastasis in T1 and T2 Gallbladder Cancer: A SEER-based Study.

Background: Gallbladder cancer (GBC) is the most common malignancy of the biliary system. Early T stage GBC patients with distant metastasis are proven to have a worse prognosis. In this study, our aim was to construct and validate a novel nomogram for predicting distant metastasis in T1 and T2 GBC. Methods: Between 2004 and 2014, patients with T1 and T2 GBC were identified in the Surveillance, Epidemiology, and End Results (SEER) database. All of the eligible patients were randomly divided into training and validation cohorts. Univariate and multivariate analyses were used to assess significant predictive factors associated with distant metastasis. A nomogram was developed and validated by a calibration curve and receptor operating characteristic curve (ROC) analysis. Results: According to the inclusion and exclusion criteria, 3013 patients with historically confirmed AJCC stage T1 and T2 GBC were enrolled. Younger age, high pathological grade, nonadenocarcinoma, T1, N1 and larger tumor size correlated positively with the risk of distant metastasis. A novel nomogram was established to predict distant metastasis in early T stage GBC patients. Internal validation with a calibration plot in the training cohort showed that this nomogram was well calibrated. Through ROC curve analysis, the areas under the ROC curves in the training and validation cohorts were 0.723 and 0.679, respectively. Conclusions: Although some limitations exist in this predictive model, the nomogram revealed the relationship between the clinicopathological characteristics of T1 and T2 GBC patients and the risk of distant metastasis. The novel nomogram will assist in patient counseling and guide treatment decision making for T1 and T2 GBC patients.