We consider the quantum version of inferring the causal relation between events. There has been recent progress towards identifying minimal interventions and observations needed. We here show, by means of constructing an explicit scheme, that quantum observations alone are sufficient for quantum causal inference for the case of a bipartite quantum system with measurements at two times. Our scheme involves the derivation of a closed-form expression for the space-time pseudo-density matrix associated with many times and qubits. This matrix can be determined by coarse-grained quantum observations alone. We show that from this matrix one can infer the causal structure via the sign of a particular function called a causal monotone. Our results show that for quantum processes one can infer the causal structure solely from correlations between observations at different times.

α-Glucosidase (AGS) inhibitors have been regarded as an ideal target for the management of type 2 diabetes mellitus (T2DM) since they can maintain an acceptable blood glucose level by delaying the digestion of carbohydrates and diminishing the absorption of monosaccharides. In the process of our endeavor in mining AGS inhibitors from natural sources, the culture broth of two mangrove-derived actinomycetes Streptomyces sp. WHUA03267 and Streptomyces sp. WHUA03072 exhibited an apparent inhibitory activity against AGS. A subsequent chemical investigation into the two extracts furnished 28 secondary metabolites that were identified by spectroscopic methods as two previously undescribed linear polyketides 1–2, four benzenoid ansamycins 3–6, fourteen cyclodipeptides 7–18, one prenylated indole derivative 19, two fusicoccane-type diterpenoids 20–21, two hydroxamate siderophore 22–23, and five others 24–28. Among all of the isolates, 11 and 24 were obtained from actinomycetes for the first time, while 20–21 had never been reported to occur in a marine-derived microorganism previously. In the in vitro AGS inhibitory assay, compounds 3, 8, 9, 11, 14, 16, and 17 exhibited potent to moderate activity with IC50 values ranging from 35.76 ± 0.40 to 164.5 ± 15.5 μM, as compared with acarbose (IC50 = 422.3 ± 8.4 μM). The AGS inhibitory activity of 3, 9, 14, 16, and 17 was reported for the first time. In particular, autolytimycin (3) represented the first ansamycin derivative reported to possess the AGS inhibitory activity. Kinetics analysis and molecular docking were performed to determine the inhibition types and binding modes of these inhibitors, respectively. In the MTT assay, 3, 8, 9, 11, 14, 16, and 17 exhibited no apparent cytotoxicity to the human normal hepatocyte (LO2) cells, suggesting satisfactory safety of these AGS inhibitors.

The construction of the innovation ecosystem plays an important role in the technology research and development activities of innovation-oriented enterprises. How to effectively promote the perfection of enterprise innovation ecology determines the quality of engineering technology activities of innovation-oriented enterprises. Entrepreneurs play a key role in enterprise innovation ecological construction, especially in resource allocation. Therefore, based on the Upper Echelon Theory, this paper investigates the "age" effect of enterprise innovation ecological construction under the influence of top managers and its economic consequences under the adjustment of various heterogeneous factors. Based on this, this paper selects the data of GEM listed companies from 2009 to 2017 as samples, uses STATA14.0 for an empirical test, constructs an OLS model with quadratic terms, and uses multiple grouping variables for a grouping regression test. The main results show that there is an inverted U-shaped relationship between the entrepreneurs' age and R&D investment, that is, due to the influence of entrepreneurs, there is a midlife crisis in R&D investment behaviors of enterprises; the test of gender grouping shows that female entrepreneurs alleviate this crisis. The conclusion of this paper reveals the influence of entrepreneur's age on enterprise innovation activities, and puts forward the important role that female managers may play in R&D activities, which provides managers with references for improving the technical level and engineering quality of innovation-oriented enterprises.

The 30-day surgical mortality metric is endorsed by the National Quality Forum for value-based purchasing purposes. However, its integrity has been questioned, as there is documented evidence of hospital manipulation of this measure, by way of inappropriate palliative care designation and changes in patient selection. To determine if there is evidence of potential manipulation, we retrospectively analyzed 1,725,291 surgical admissions from 158 United States hospitals participating in the National Inpatient Sample from 2010 to 2011. As a way of evaluating unnecessary life-prolonging measures, we determined that a significant increase in mortality rate after post-operative day 30 (day 31–35) would indicate manipulation. We compared the post-operative mortality rates for each hospital between Post-Operative Day 26–30 and Post-Operative Day 31–35 using Wilcoxon signed-rank tests. After application of the Bonferroni correction, the results showed that none of the hospitals had a statistically significant increase in mortality after post-operative day 30. This analysis fails to impugn the integrity of this measure, as we did not identify any evidence of potential manipulation of the 30-day surgical mortality metric.