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The invention of Chinese paktong was well-known in ancient China from at least the fourth century AD and is considered to be one of the most important inventions in the history of metallurgy, facilitating economic and material exchange in the West during the 17-19th centuries. As recent investigations into the relevant archives of paktong show, it is recognized that the early industry of such metal had intimate connections with Yunnan and Sichuan provinces. Due to the recent year research on some ancient metallurgical remains of Chinese paktong in Yunnan, it shows that the slags in the sites of Mouding and Jiangyin were from the specific metallurgical process, probably by intentionally accumulating nickel with iron. Both sites were likely to be the places of mining or refining and roasting the ores, but the outcomes from them might be the roughly finished products.

Objective: We explored whether medical health workers had more psychosocial problems than nonmedical health workers during the COVID-19 outbreak. Methods: An online survey was run from February 19 to March 6, 2020; a total of 2,182 Chinese subjects participated. Mental health variables were assessed via the Insomnia Severity Index (ISI), the Symptom Check List-revised (SCL-90-R), and the Patient Health Questionnaire-4 (PHQ-4), which included a 2-item anxiety scale and a 2-item depression scale (PHQ-2). Results: Compared with nonmedical health workers (n = 1,255), medical health workers (n = 927) had a higher prevalence of insomnia (38.4 vs. 30.5%, p < 0.01), anxiety (13.0 vs. 8.5%, p < 0.01), depression (12.2 vs. 9.5%; p< 0.04), somatization (1.6 vs. 0.4%; p < 0.01), and obsessive-compulsive symptoms (5.3 vs. 2.2%; p < 0.01). They also had higher total scores of ISI, GAD-2, PHQ-2, and SCL-90-R obsessive-compulsive symptoms (p ≤ 0.01). Among medical health workers, having organic disease was an independent factor for insomnia, anxiety, depression, somatization, and obsessive-compulsive symptoms (p < 0.05 or 0.01). Living in rural areas, being female, and being at risk of contact with COVID-19 patients were the most common risk factors for insomnia, anxiety, obsessive-compulsive symptoms, and depression (p < 0.01 or 0.05). Among nonmedical health workers, having organic disease was a risk factor for insomnia, depression, and obsessive-compulsive symptoms (p < 0.01 or 0.05). Conclusions: During the COVID-19 outbreak, medical health workers had psychosocial problems and risk factors for developing them. They were in need of attention and recovery programs.

We report the Fandian biota, a new Konservat-Lagerstatte from the Cambrian Stage 3 Yuxiansi and Jiulaodong Formations in Sichuan, South China, with close faunal links to the Chengjiang biota in Yunnan. The biodiversity of the Fandian biota includes total-group euarthropods (radiodonts, bivalved forms, acercostracans, trilobites, non-biomineralized trilobitomorphs), armoured lobopodians, palaeoscolecids, pedunculate brachiopods, hyoliths, chancelloriids, sponges, and filamentous algae. Benthic dwellers dominate the fossil community (e.g. trilobitomorphs, brachiopods, sponges), with rare instances of nektonic (radiodonts, bivalved euarthropods) and infaunal (palaeoscolecids) organisms. The Fandian biota contains soft-bodied taxa that were only known from Chengjiang and Xiaoshiba until now, namely Primicaris (acercostracan), Xandarella (non-trilobite trilobitomorph) and Mafangscolex (palaeoscolecid), expanding the distribution of these previously endemic taxa beyond Yunnan to the northern Yangtze Platform during the Cambrian Stage 3. Our findings provide a more comprehensive understanding of early Cambrian biodiversity that inhabited the Yangtze Platform over a substantially greater palaeobiogeographic distribution than previously considered.

AIM: To evaluate the oncological outcomes of transanal local excision and the need for immediate conventional reoperation in the treatment of patients with high risk T1 rectal cancers. METHODS: Twenty five high risk T1 rectal cancers treated by transanal local excision at the Guangdong General Hospital were analyzed retrospectively. Twelve patients received transanal local excision and 13 patients underwent subsequent immediate surgical rescue after transanal local excision within 4 wk. Differences in the local recurrence rates and 5-year overall survival rates between the two groups were analyzed. The prognostic value of immediate conventional reoperation for high risk T1 rectal cancers was also evaluated. RESULTS: The median follow-up period was 62 mo. The local recurrence rates after transanal local excision for high risk T1 rectal cancer were 50%. By immediate conventional reoperation, the local recurrence rates were significantly reduced to 7.7%. The difference be tween these two groups was statistically significant ( P = 0.030). Kaplan-Meier survival analysis showed a trend for decreased 5-year overall survival rates for patients treated by transanal local excision compared with immediate conventional reoperation (63% vs 89%). CONCLUSION: Transanal local excision cannot be considered sufficient treatment for patients with high risk T1 rectal cancers. Immediate conventional reoperation should be performed if the pathology of the local excision is high risk.

AIM: To explore the risk factors for local recurrence of middle and lower rectal carcinoma after curative resection. METHODS: Specimens of middle and lower rectal carcinoma from 56 patients who received curative resection at the Department of General Surgery of Guangdong Provincial People’s Hospital were studied. A large slice technique was used to detect mesorectal metastasis and evaluate circumferential resection margin status. The relations between clinicopathologic characteristics, mesorectal metastasis and circumferential resection margin status were identified in patients with local recurrence of middle and lower rectal carcinoma. RESULTS: Local recurrence of middle and lower rectal carcinoma after curative resection occurred in 7 of the 56 patients (12.5%), and was significantly associated with family history (χ2 = 3.929, P = 0.047), high CEA level (χ2 = 4.964, P = 0.026), cancerous perforation (χ2 = 8.503, P = 0.004), tumor differentiation (χ2 = 9.315, P = 0.009) and vessel cancerous emboli (χ2 = 11.879, P = 0.001). In contrast, no significant correlation was found between local recurrence of rectal carcinoma and other variables such as age (χ2 = 0.506, P = 0.477), gender (χ2 = 0.102, χ2 = 0.749), tumor diameter (χ2 = 0.421, P = 0.516), tumor infiltration (χ2 = 5.052, P = 0.168), depth of tumor invasion (χ2 = 4.588, P = 0.101), lymph node metastases (χ2 = 3.688, P = 0.055) and TNM staging system (χ2 = 3.765, P = 0.152). The local recurrence rate of middle and lower rectal carcinoma was 33.3% (4/12) in patients with positive circumferential resection margin and 6.8% (3/44) in those with negative circumferential resection margin. There was a significant difference between the two groups (χ2 = 6.061, P = 0.014). Local recurrence of rectal carcinoma occurred in 6 of 36 patients (16.7%) with mesorectal metastasis, and in 1 of 20 patients (5.0%) without mesorectal metastasis. However, there was no significant difference between the two groups (χ2 = 1.600, P = 0.206). CONCLUSION: Family history, high CEA level, cancerous perforation, tumor differentiation, vessel cancerous emboli and circumferential resection margin status are the significant risk factors for local recurrence of middle and lower rectal carcinoma after curative resection. Local recurrence may be more frequent in patients with mesorectal metastasis than in patients without mesorectal metastasis.

To evaluate the risk factors of lateral lymph node metastasis in advanced lower rectal cancer and its correlation with local recurrence and prognosis.Data from 96 consecutive patients with advanced lower rectal cancer underwent curative surgery with lateral dissection were retrospectively analyzed. The correlations of lateral lymph node metastasis with clinicopathologic characteristics, local recurrence and prognosis were investigated.Lateral lymph node metastasis was observed in 14.6 (14/96) of the cases. In 40 patients with tumor diameteror = 5 cm, 10 (25.0%) patients were found with lateral lymph node metastasis; while in the other 56 patients, only 4 (7.1%) cases were found with lateral lymph node metastasis (P0.05). Lateral lymph node metastasis was more frequent in patients whose tumor infiltrated full range of the intestinal wall (70%) than patients with 3/4, 2/4 and 1/4 intestinal wall was infiltrated (12.0%, 6.7% and 6.3%, respectively) (P0.05). Lateral lymph node metastasis rate of poorly differentiated carcinomas was significantly higher than those of moderate and well-differentiated ones (30% vs. 9.1% and 4.5%, P0.05). Local recurrence occurred in 18.8% (18 of 96 cases) of patients. Local recurrence in patients with positive lateral lymph node metastasis was 64.3%, while 11.0% in those without lateral lymph node metastasis (P0.05). Kaplan-Meier survival analysis showed significant improvements in median survival for patients with negative lateral lymph node metastasis over patients with lateral lymph node metastasis (80.9 +/- 2.1 vs. 38 +/- 6.7 months, log-rank P0.05).Tumor diameter, degree of tumor infiltration and histological differentiation are significant risk factors of lateral lymph node metastasis in advanced lower rectal cancer. Lateral lymph node metastasis is an important predictor of local recurrence and prognosis of patients.

AIM: To evaluate the risk factors for lateral lymph node metastasis in patients with advanced low rectal cancer, in order to make the effective selection of patients who could benefit from lateral lymph node dissection, as well as the relationship of lateral lymph node metastasis with local recurrence and survival of patients with advanced low rectal cancer. METHODS: A total of 96 consecutive patients who underwent curative surgery with lateral pelvic lymphadenectomy for advanced lower rectal cancer were retrospectively analyzed. The relation of lateral lymph node metastasis with clinicopathologic characteristics, local recurrence and survival of patients was identified. RESULTS: Lateral lymph node metastasis was observed in 14.6% (14/96) of patients with advanced low rectal cancer. Lateral lymph node metastasis was detected in 10 (25.0%) of 40 patients with tumor diameter ≥ 5 cm and in 4 (7.1%) of 56 patients with tumor diameter < 5 cm. The difference between the two groups was statistically significant (χ2 = 5.973, P = 0.015). Lateral lymph node metastasis was more frequent in patients with 4/4 diameter of tumor infiltration (7 of 10 cases, 70.0%), compared with patients with 3/4, 2/4 and 1/4 diameter of tumor infiltration (3 of 25 cases, 12.0%; 3 of 45 cases, 6.7%; 1 of 16 cases, 6.3%) (χ2 = 27.944, P = 0.0001). The lateral lymph node metastasis rate was 30.0% (9 of 30 cases), 9.1% (4 of 44 cases) and 4.5% (1 of 22 cases) for poorly, moderately and well-differentiated carcinoma, respectively. The difference between the three groups was statistically significant (χ2 = 8.569, P = 0.014). Local recurrence was 18.8% (18 of 96 cases), 64.3% (9 of 14 cases), and 11.0% (9 of 82 cases) in patients with advanced low rectal cancer, in those with and without lateral lymph node metastasis, respectively. The difference between the two groups was statistically significant (χ2 = 22.308, P = 0.0001). Kaplan-Meier survival analysis showed significant improvements in median survival (80.9 ± 2.1 m, 95% CI: 76.7-85.1 m vs 38 ± 6.7 m, 95% CI: 24.8-51.2 m) of patients without lateral lymph node metastasis compared with those with lateral lymph node metastasis (log-rank, P = 0.0001). CONCLUSION: Tumor diameter, infiltration and differentiation are significant risk factors for lateral lymph node metastasis. Lateral pelvic lymphadenectomy should be performed following surgery for patients with tumor diameter ≥ 5 cm. Lateral lymph node metastasis is an important predictor for local recurrence and survival in patients with advanced low rectal cancer.

AIM: To clarify the relationship between circumferential resection margin status and local and distant recurrence as well as survival of patients with middle and lower rectal carcinoma. The relationship between circumferential resection margin status and clinicopathologic characteristics of middle and lower rectal carcinoma was also evaluated. METHODS: Cancer specimens from 56 patients with middle and lower rectal carcinoma who received total mesorectal excision at the Department of General Surgery of Guangdong Provincial People’s Hospital were studied. A large slice technique was used to detect mesorectal metastasis and evaluate circumferential resection margin status. RESULTS: Local recurrence occurred in 12.5% (7 of 56 cases) of patients with middle and lower rectal carcinoma. Distant recurrence occurred in 25% (14 of 56 cases) of patients with middle and lower rectal carcinoma. Twelve patients (21.4%) had positive circumferential resection margin. Local recurrence rate of patients with positive circumferential resection margin was 33.3% (4/12), whereas it was 6.8% (3/44) in those with negative circumferential resection margin (P = 0.014). Distant recurrence was observed in 50% (6/12) of patients with positive circumferential resection margin; conversely, it was 18.2% (8/44) in those with negative circumferential resection margin (P = 0.024). Kaplan-Meier survival analysis showed significant improvements in median survival (32.2 ± 4.1 mo, 95% CI: 24.1-40.4 mo vs 23.0 ± 3.5 mo, 95% CI: 16.2-29.8 mo) for circumferential resection margin-negative patients over circumferential resection margin-positive patients (log-rank, P < 0.05). 37% T3 tumors examined were positive for circumferential resection margin, while only 0% T1 tumors and 8.7% T2 tumors were examined as circumferential resection margin. The difference between these three groups was statistically significant (P = 0.021). In 18 cancer specimens with tumor diameter ≥ 5 cm 7 (38.9%) were detected as positive circumferential resection margin, while in 38 cancer specimens with a tumor diameter of < 5 cm only 5 (13.2%) were positive for circumferential resection margin (P = 0.028). CONCLUSION: Our findings indicate that circumferential resection margin involvement is significantly associated with depth of tumor invasion and tumor diameter. The circumferential resection margin status is an important predictor of local and distant recurrence as well as survival of patients with middle and lower rectal carcinoma.

To detect mesorectal metastasis of middle and lower rectal cancer and to evaluate its relationship with clinicopathologic characteristics.Cancer specimens resected from 56 patients with middle and lower rectal cancer who received total mesorectal excision were examined by routine pathologic observation. The relationship between mesorectal metastasis and clinicopathologic characteristics of middle and lower rectal cancer was also investigated.Mesorectal metastasis was detected in 36 (64.3%) of 56 cancer specimens. In 18 cancer specimens with tumor diameteror = 5 cm, 15 (83.3%) were detected mesorectal metastasis, while in 38 cancer specimens with tumor diameter5 cm only 21 (55.3%) were detected mesorectal metastasis (P = 0.041). Mesorectal metastasis was more frequent in T(3) cancer specimens (81.5%) and T(2) cancer specimens (56.6%), compared with T(1) cancer specimens (1/6) (P = 0.007). 85.7% poorly differentiated cancer specimens were detected mesorectal metastasis, while moderate and well-differentiated cancer specimens were only 63.2% and 1/5 respectively (P = 0.028). Mesorectal metastasis was more frequent in stage III cancer specimens (100%), compared with stage II and I cancer specimens (27.3% and 1/5 respectively, P = 0.000). No significant correlations were found between mesorectal metastasis and other variables such as age, gender and Ming classification (P0.05).Mesorectal metastasis of middle and lower rectal cancer has significant correlation with tumor diameter, tumor invasion, tumor differentiation and TNM stage. Total mesorectal excision oror = 5 cm mesorectal distal to the rectal tumor should be followed in the management of middle and lower rectal cancer.

To examine the expression of matrix metalloproteinase-2 (MMP-2) and to evaluate its correlation with mesorectal metastasis in middle and lower rectal cancer.The resected primary tumors from 56 patients with middle and lower rectal cancer who received total mesorectal excision were studied from Dec. 2001 to Jul. 2003.The MMP-2 expression was positive in 42 (75%) cases. The positive rate of MMP-2 expression was 88.9% in T3 tumors and 69.6 % in T2 tumors respectively, while only 33.3% in T1 tumors (P=0.013). MMP-2 was positive in 91.2% (31/34) infiltrative rectal carcinomas while 40.0% (6/15) expansive rectal carcinomas (P=0.001). Mesorectal metastasis was detected in 36 (64.3%) of 56 cases. The expression of MMP-2 was positive in 31 (86.1%) of the 36 patients with mesorectal metastasis, while in 11(55%) of the 20 patients without mesorectal metastasis (P=0.01).The expression of MMP-2 in middle and lower rectal cancer is significantly associated with depth of tumor invasion and Ming classifications. The high expression of MMP-2 may play an important role in the development of mesorectal metastasis in middle and lower rectal cancer.