Effects of case- and population-based COVID-19 interventions in Taiwan

In the first wave of the COVID-19 pandemic, broad usage of non-pharmaceutical interventions played a crucial role in controlling epidemics1-6. However, the substantial economic and societal costs of continuous use of border controls, travel restrictions, and physical distancing measures suggest that these measures may not be sustainable and that policymakers have to seek strategies to lift the restrictions. Taiwan was one of the few countries that demonstrated initial success in eliminating the COVID-19 outbreak without strict lockdown or school closure. To understand the key contributors to the successful control, we applied a stochastic branching model to empirical case data to evaluate and compare the effectiveness of more targeted case-based (including contact tracing and quarantine) and less targeted population-based interventions (including social distancing and face mask use) in Taiwan. We found that case-based interventions alone would not be sufficient to contain the epidemic, even in a setting where a highly efficient contact tracing program was in place. The voluntary population-based interventions have reduced the reproduction numbers by more than 60% and have likely played a critical role at the early stage of the outbreak. Our analysis of Taiwans success highlights that coordinated efforts from both the government and the citizens are indispensable in the fight against COVID-19 pandemic.

High transmissibility of COVID-19 near symptom onset

BackgroundThe dynamics of coronavirus disease 2019 (COVID-19) transmissibility after symptom onset remains unknown. MethodsWe conducted a prospective case-ascertained study on laboratory-confirmed COVID-19 cases and their contacts. Secondary clinical attack rate (considering symptomatic cases only) was analyzed for different exposure windows after symptom onset of index cases and for different exposure settings. ResultsThirty-two confirmed patients were enrolled and 12 paired data (index-secondary cases) were identified among the 1,043 contacts. The secondary clinical attack rate was 0.9% (95% CI 0.5-1.7%). The attack rate was higher among those whose exposure to index cases started within five days of symptom onset (2.4%, 95% CI 1.1-4.5%) than those who were exposed later (zero case from 605 close contacts, 95% CI 0-0.61%). The attack rate was also higher among household contacts (13.6%, 95% CI 4.7-29.5%) and non- household family contacts (8.5%, 95% CI 2.4-20.3%) than that in healthcare or other settings. The higher secondary clinical attack rate for contacts near symptom onset remained when the analysis was restricted to household and family contacts. There was a trend of increasing attack rate with the age of contacts (p for trend < 0.001). ConclusionsHigh transmissibility of COVID-19 near symptom onset suggests that finding and isolating symptomatic patients alone may not suffice to contain the epidemic, and more generalized social distancing measures are required. Rapid reduction of transmissibility over time implies that prolonged hospitalization of mild cases might not be necessary in large epidemics.

Research progress on chemical constituents and biological activities from Turpinia species / 中国中药杂志

Turpinia species have been used as local Chinese medicines. It has been widely concerned about their antibacterial and anti-inflammatory effects. Modern studies showed that the chemical constituents of Turpina species include flavonoids, triterpenoids, megastigans and phenoli acids. Its pharmacological research mainly focused on antibacterial, anti-inflammatory, antioxidant, analgesic, and immuneregulation effect. In this paper, the chemical compositions and pharmacological activities of Turpinia species were summarized, in order to provide scientific basis for the further development and utilization of Turpinia species.

Study on chemical constituents of flavonoids in Turpinia arguta / 药学学报

Fifteen flavonoids were isolated and identified by macroporous resin column chromatography, polyamide column chromatography, silica gel column chromatography, ODS column chromatography and preparative liquid chromatography from the ethanol extract Turpinia arguta. Their structures of these flavonoids were identified by NMR and mass spectrometry as argutoside F (1), luteolin-7-O-α-L-rhamanopyranosyl-(1→2)-α-L-rhamnopyranosyl-(1→6)-β-D-glucopyranoside (2), nuezhenoside (3), acacetin-7-O-α-L-rhamnopyranosyl-(1→2)-α-L-rhamnopyranosyl-(1→6)-β-D-glucopyranoside (4), apigenin (5), quercetin (6), quercetin-3-O-α-L-rhamnopyranosyl-(1→6)-β-D-glucopyranoside (7), rhoifolin (8), luteolin-7-O-α-L-rhamanopyranosyl-(1→2)-β-D-glucopyranoside (9), acacetin-7-O-α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranoside (10), luteolin-7-O-β-D-glucopyranoside (11), luteolin (12), neodiosmin (13), apigenin-7-O-rutinoside (14), and quercetin-3-O-α-L-arabinopyranoside (15). Compound 1 is new, whereas compound 2, 7, 9, 13-15 were obtained from this plant for the first time.

Sesquiterpenes with anti-metastasis breast cancer activity from Chloranthus henryi / 中国中药杂志

To study sesquiterpenes with anti-metastasis breast cancer activity from Chloranthus henryi, ten sesquiterpenes ,zedoarofuran (1), chlorajapolide D (2), 4β, 8β-dihydroxy-5α(H)-eudesm-7(11)-en-8, 12-olide (3), curcolonol (4), lasianthuslactone A (5), chlomultin C (6), (1E,4Z)-8-hydroxy-6-oxogermacra-1(10), 4, 7(11) -trieno-12, 8-lactone (7), shizukanolide E (8) , shizukanolide F (9) , 9α-hydroxycurcolonol (10), and five bis-sesquiterpenes, shizukaol B (11), shizukaol C (12) , cycloshizukaol A (13) , sarcandrolide B (14) , henriol A(15), were isolated by using different kinds of column chromatography methods from the ethyl acetate part of Ch.henryi and their structures were identified based on spectroscopic methods. Compounds 2, 8, 9, and 10 were obtained from the genus Chloranthus for the first time. Compounds 2, 5, 8-10, 12,and 14 were obtained from this plant for the first time. Some isolated compounds were subjected to evaluate the anti-metastasis breast cancer activity by using pharmacological methods, and only compounds 4, 11, and 12 were potent active.