Over the past years a continuously expanding list of ecological indicators termed "footprint" has been introduced to the scientific community, with the aim of assisting policy makers in better ...understanding the pressures that humanity places upon our planet. The mathematics behind the criterion of strong sustainability, for instance, has been demonstrated from the perspective of ecological footprint. A three-dimensional (3D) model of the ecological footprint has been developed for the measurement of the human-induced natural capital use. This paper starts from the idea of operationalizing the 3D model in a more accurate and robust way. To that end, we critically review the classical version of the 3D model, and propose to prevent unintended deficit shifting by tracking the appropriation of the capital flows and the depletion of the capital stocks among diverse types of land use. Ultimately, this paper lays out some priorities for further improving natural capital assessment through the combination of footprin
•The concept of absolute environmental sustainability (AES) has not yet influenced policies.•AES indicators informed by planetary boundaries (PBs) are emerging.•We examine the role of PBs in ...assessing AES across scales and present a critique of the progress made.•Consensus need to be sought in standardising and harmonising safe operating spaces.•Respecting biophysical limits and improving human well-being should be formulated in AES indicators.
The idea of revisiting the biophysical limits of human life on planet Earth has gained renewed momentum in the Anthropocene. The planetary boundaries (PBs) framework has emerged as a strong guardrail concept, even though its capacity to inform the development of absolute sustainability assessments and realistic policies remains unclear. In this paper, we present a current synthesis of the development of absolute environmental sustainability (AES) indicators and assessments informed by PBs. We firstly explore how PBs have been considered in AES research at different scales. We then present a critique of how consensus could be reached in standardising and harmonising the share of globally and locally allocated safe operating spaces. We argue that PBs must be linked to human consumption as the main socio-economic driver and that planetary concerns can only be addressed through a holistic perspective that encompasses global tele-connections. Based on our findings, we provide recommendations for the future design of AES indicators and assessments informed by PBs.
As an important platform molecule, atropisomeric QUINOL plays a crucial role in the development of chiral ligands and catalysts in asymmetric catalysis. However, efficient approaches towards QUINOL ...remain scarce, and the resulting high production costs greatly impede the related academic research as well as downstream industrial applications. Here we report a direct oxidative cross-coupling reaction between isoquinolines and 2-naphthols, providing a straightforward and scalable route to acquire the privileged QUINOL scaffolds in a metal-free manner. Moreover, a NHC-catalyzed kinetic resolution of QUINOL N-oxides with high selectivity factor is established to access two types of promising axially chiral Lewis base catalysts in optically pure forms. The utility of this methodology is further illustrated by facile transformations of the products into QUINAP, an iconic ligand in asymmetric catalysis.
Numerous studies have used human pluripotent stem cell-derived cerebral organoids to elucidate the mystery of human brain development and model neurological diseases in vitro, but the potential for ...grafted organoid-based therapy in vivo remains unknown. Here, we optimized a culturing protocol capable of efficiently generating small human cerebral organoids. After transplantation into the mouse medial prefrontal cortex, the grafted human cerebral organoids survived and extended projections over 4.5 mm in length to basal brain regions within 1 month. The transplanted cerebral organoids generated human glutamatergic neurons that acquired electrophysiological maturity in the mouse brain. Importantly, the grafted human cerebral organoids functionally integrated into pre-existing neural circuits by forming bidirectional synaptic connections with the mouse host neurons. Furthermore, compared to control mice, the mice transplanted with cerebral organoids showed an increase in freezing time in response to auditory conditioned stimuli, suggesting the potentiation of the startle fear response. Our study showed that subcortical projections can be established by microtransplantation and may provide crucial insights into the therapeutic potential of human cerebral organoids for neurological diseases.
The modification of soil organic matter (SOM) decomposition by plant carbon (C) input (priming effect) represents a critical biogeochemical process that controls soil C dynamics. However, the ...patterns and drivers of the priming effect remain hidden, especially over broad geographic scales under various climate and soil conditions. By combining systematic field and laboratory analyses based on multiple analytical and statistical approaches, we explore the determinants of priming intensity along a 2200 km grassland transect on the Tibetan Plateau. Our results show that SOM stability characterized by chemical recalcitrance and physico-chemical protection explains more variance in the priming effect than plant, soil and microbial properties. High priming intensity (up to 137% of basal respiration) is associated with complex SOM chemical structures and low mineral-organic associations. The dependence of priming effect on SOM stabilization mechanisms should be considered in Earth System Models to accurately predict soil C dynamics under changing environments.
Mixtures of two-component normal distributions (MixN) have various applications in statistical inference with flexibility in density fitting. The best estimation of the five model parameters still ...represents a challenge. This article proposes more accurate density fittings given a random sample in both the moment-based and likelihood-based estimation frameworks. Motivated by the excellent performance of the Quasi-Monte Carlo method in quantile estimations, we propose an innovative approach to improve the accuracy of parameter estimations by reinforcing the representativeness of observed data via the distribution-free Harrell-Davis quantile estimators. The revision on the penalized maximum likelihood method is also considered due to the unpleasant properties of the original likelihood function under MixN. The bootstrap bias-corrected moment estimators are given as another revision. A sequential algorithm for optimization (SNTO) is conducted in finding numerical solutions for the two types of parameter estimation methods. SNTO is more adapted to MixN and shows strong advantages in the likelihood-based estimation compared to the famous EM algorithm. Simulation results show that our proposed approach can effectively improve estimation accuracy and increase resistance to small sample sizes and/or high percent overlaps between two mixture components. A real data example is given to illustrate the efficiency of our proposed methods.
Metal‐polarized aza‐ortho‐quinone methides (aza‐o‐QMs) are a unique and efficient handle for azaheterocycle synthesis. Despite great achievements, the potential of these reactive intermediates has ...not yet been fully exploited, especially the new reaction modes. Herein, we disclosed an unprecedented dearomatization process of metal‐polarized aza‐o‐QMs, affording transient dearomatized spiroaziridine intermediates. Based on this serendipity, we accomplished three sequential dearomatization‐rearomatization reactions of benzimidazolines with aza‐sulfur ylides, enabling the divergent synthesis of bis‐nitrogen heterocycles with high efficiency and flexibility. Moreover, experimental and theoretical studies were performed to explain the proposed mechanisms and observed selectivity. Further cellular evaluation of the dibenzodiazepine products identified a hit compound for new antitumor drugs.
Three sequential dearomatization‐rearomatization reactions of benzoxazinones with aza‐sulfur ylides were developed under transition metal catalysis. Pharmaceutically significant bis‐nitrogen heterocycles, benzimidazolines and dibenzodiazepines, were produced with high efficiency and selectivity. Furthermore, detailed mechanism studies were carried out to explain the proposed mechanism and reaction selectivity.
Iliosacral screw fixation is a popular method for the management of posterior pelvic ring fractures or dislocations, providing adequate biomechanical stability. Our aim in this study was to describe ...the use of a new patient-specific external template to guide the insertion of iliosacral screws and to evaluate the efficacy and safety of this technique compared with the conventional fluoroscopy-guided technique.
This was a retrospective study of patients with incomplete or complete posterior pelvic ring disruptions who required iliosacral screw fixation. For analysis, patients were divided into two groups: the external template group (37 screws in 22 patients) and the conventional group (28 screws in 18 patients). The operative time per screw, radiation exposure time and the rate of screw perforation (accuracy) were compared between groups. In the external template group, the difference between the actual and planned iliosacral screw position was also compared.
In the conventional group, the average operative time per screw was 39.7 ± 10.6 min, with an average radiation exposure dose of 1904.0 ± 844.5 cGy/cm
, with 4 cases of screw perforation. In the external template group, the average operative time per screw was 17.9 ± 4.7 min, with an average radiation exposure dose of 742.8 ± 230.6 cGy/cm
and 1 case of screw perforation. In the template group, the mean deviation distance between the actual and planned screw position was 2.75 ± 1.0 mm at the tip, 1.83 ± 0.67 mm in the nerve root tunnel zone and 1.52 ± 0.48 mm at the entry point, with a mean deviation angle of 1.73 ± 0.80°.
The external template provides an accurate and safe navigation tool for percutaneous iliosacral screw insertion that could decrease the operative time and radiation exposure.
China has limited arable land area, and its output value is increased with enhanced agricultural inputs such as machinery, irrigation, fertilizers, and pesticides. However, this mode is accompanied ...by an increase in agricultural carbon emissions. With the aim to further examine the driving effect of scientific and technological innovation on economic growth and green agriculture, this study uses the Solow growth model coupled with the Cobb-Douglas production function and vector autoregressive models. Then, the agricultural scientific and technological innovation capacity in Guangdong Province during 2006-2020 is evaluated by using the contribution rate of agricultural scientific and technological progress (ASTP) as the assessment index. In addition, the carbon footprints of green agricultural indexes such as machinery, irrigation, fertilizers, and pesticides are measured to analyze the relationship between green agriculture and agricultural scientific and technological innovation capacity. Results demonstrate the gradual increase in the contribution rate of ASTP in Guangdong Province. During the 11th, 12th, and 13th Five-Year Plan periods, the rates were 65.09%, 65.94%, and 70.40%, respectively, indicating that the agricultural scientific and technological innovation ability constantly improved. Among the indexes of green agriculture, the carbon footprints of machinery have a significant impact on agricultural scientific and technological innovation, which is quickly transformed into machinery. Such innovation requires the driving force of science and technology itself, which have relatively significant and rapid effects. On the basis of the results, corresponding policy suggestions are proposed: increasing investments in scientific and technological innovation in the agricultural field, vigorously developing new energy-saving and emission reduction products and processes for fertilizers, and increasing the research and promotion of agricultural machinery. The proposed method provides good prospects for the development of agricultural production towards mechanization, intelligence, efficiency, and greenness.
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