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Over the past one and a half centuries, urbanization has coincided with industrialization and globalization. The business as usual mode of urban development has proven unsustainable, and the consensus of developing new paradigms toward more sustainable trajectories has been reached. This paper reviews and identifies the most prominent forms of sustainable urban development, encompassing theories of urban frameworks, major definitions and concepts and historical developments in the East Asian context. Three major trends are assessed, including garden cities (and eco‐cities), low‐carbon cities and smart cities, which identify each main phase of sustainable urbanization in the East Asian context. [ABSTRACT FROM AUTHOR]

Nepal, the world's second most water‐rich country, nevertheless struggles to provide sufficient domestic electricity. Despite Nepal's potential to become the hydropower source for South Asia, it still relies heavily on importing electricity from India. This paper investigates why Nepal's hydropower capacity is inadequately utilized from both domestic and international perspectives and finds that domestic factors such as geo‐climate features, weak infrastructure, political instability, and institutional deficiencies significantly hinder Nepal's hydropower development. From an international perspective, Nepal's geopolitical bonds and energy dependency with India and the regional power‐sharing configuration have significantly influenced its hydropower policy‐making. Furthermore, this paper proposes how Nepal could sustainably develop its hydropower for self‐sufficiency by establishing better policy instruments, attracting foreign investments, and upgrading its electricity infrastructure. [ABSTRACT FROM AUTHOR]

2D semiconducting transition metal dichalcogenides (TMDCs) have emerged as essential building blocks for engineering next‐generation integrated electronics. To achieve this, the controllable synthesis of monolayer TMDCs with high crystal quality, low cost, and high yield is crucial, while it remains challenging. Herein, the direct synthesis of large‐area uniform, millimeter‐size monolayer MoSe2 single crystals on a 6‐centimeter‐long soda‐lime glass template, by using a designed "beam‐bridge" assisted metal oxide precursor feeding strategy via chemical vapor deposition (CVD), is reported. Notably, several tenths of millimeter‐scale, triangular‐shaped monolayer MoSe2 single crystals are obtained in one batch within 25 s' growth, affording so far the fastest growth rate (≈50 µm s−1). This ultrafast growth behavior is proposed to be mediated by the sufficient, homogeneous release of Mo‐based precursor, the catalytic property of sodium atoms on soda‐lime glass substrate, as well as the improved surface kinetics on the molten glass surface. Moreover, the thickness‐controlled growth from monolayer to bilayers is also realized. This work provides brand new insights for the batch production of large single‐crystal TMDCs, which should propel its practical applications in versatile fields. [ABSTRACT FROM AUTHOR]

Modulating electronic structure of monolayer transition metal dichalcogenides (TMDCs) is important for many applications, and doping is an effective way toward this goal, yet is challenging to control. Here, the in situ substitutional doping of niobium (Nb) into TMDCs with tunable concentrations during chemical vapor deposition is reported. Taking monolayer WS2 as an example, doping Nb into its lattice leads to bandgap changes in the range of 1.98–1.65 eV. Noteworthy, electrical transport measurements and density functional theory calculations show that the 4d electron orbitals of the Nb dopants contribute to the density of states of Nb‐doped WS2 around the Fermi level, resulting in an n‐ to p‐type conversion. Nb‐doping also reduces the energy barrier of hydrogen absorption in WS2, leading to an improved electrocatalytic hydrogen evolution performance. These results highlight the effectiveness of controlled doping in modulating the electronic structure of TMDCs and their use in electronic related applications. [ABSTRACT FROM AUTHOR]

Periodontal disease (PD), as a chronic bacterial infection, might cause cardiovascular and some other systemic diseases, with recent studies reporting that it exhibits some connection with lung cancer. While studies have shown that poor oral health might increase the risk of lung cancer, the veracity of these reports is questionable. Therefore, this meta‐analysis was undertaken to investigate the association between PD and the risk of lung cancer. A search was run in PubMed, EMBASE, MEDLINE, CENTRAL, and ClinicalTrials.gov databases up to January 1, 2020. Cohort and case‐control studies investigating the correlation between PD and lung cancer were included. Eligibility assessment and data extraction were conducted independently, and a meta‐analysis was performed to synthesize the data. The association between PD, edentulism, and lung cancer was measured by the adjusted hazard ratios (HRs) or odds ratios (ORs) and their 95% confidence intervals (CIs) provided in articles. We employed appropriate effect model in terms of I2 (a fixed‐effect model for PD and a random‐effect model for edentulism) to obtain summary effect estimates. Statistical heterogeneity was investigated by chi‐square test and I2 statistics. Newcastle‐Ottawa Scale (NOS) was used to assess the quality of their method. Six cohort studies (eight references) and two case‐control studies, assessed as high‐quality, involving 167 256 participants, were included in the review. The summary estimates based on adjusted data showed an association between PD and a significant risk of lung cancer both in cohort studies (HR = 1.40, 95% CI = 1.25‐1.58; I2 = 8.7%) and case‐control studies (OR = 1.51, 95% CI = 1.16‐1.98; I2 = 36.5%). Similar features were found in the sensitivity analysis and subgroups for six cohort studies, of male only (HR = 1.36, 95% CI = 1.15‐2.60), setting the lung cancer incidence as endpoint (HR = 1.39, 95% CI = 1.24‐1.57; I2 = 23.9%), and adjusting alcohol for multifactorial HR (HR = 1.38, 95% CI = 1.21‐1.57; I2 = 39.9%). The summary HR for edentulism was 1.93 (95% CI = 1.05‐3.57; I2 = 55.3%). No obvious publication bias was detected. This systematic review and meta‐analysis demonstrated a significant association between PD and the incidence of lung cancer. Further observational studies are required by using standardized measurements to assess the periodontal status and by eliminating confounding factors, such as alcohol and diabetes, to verify such a relationship. [ABSTRACT FROM AUTHOR]

Different dispersion near the electronic band edge of a semiconductor can have great influence on its transport, thermoelectric, and optical properties. Using first‐principles calculations, it is demonstrated that a new phase of group‐IV monochalcogenides (γ‐MX, M = Ge, Sn; X = S, Se, or Te) can be stabilized in monolayer limit. γ‐MXs are shown to possess a unique band dispersion—that is, camel's back like structure—in the top valence band. The band nesting effect near the camel's back region induces a large excitonic absorbance and significantly different exciton behaviors from other 2D materials. Importantly, the small effective mass and the indirect characteristics of lowest‐energy exciton render it advantageous for the generation of electron–hole liquid state. After careful evaluation of the electron–hole dissociation temperature and the Mott critical density, it is predicted that a high‐temperature exciton gas to electron–hole liquid phase transition can be achieved in these materials with a low excitation power density. The findings open up new opportunities for both the fundamental research on exciton physics and design of excitonic devices based on 2D materials with distinct band dispersion. [ABSTRACT FROM AUTHOR]

The International Associations for Dental Research (IADR) annual meeting is one of the most important dental meetings throughout the world, and researches about paediatric dentistry presented in this platform are often used to guide clinical work. To evaluate the publication outcomes of oral and poster paediatric proceedings, which were accepted by the International Associations for Dental Research (IADR), annual meetings from 2010 to 2016 and to analyse the possible factors influencing an abstract's progression to publication. Oral and poster abstracts were retrieved from the official website of IADR (2010‐2016). Searching for subsequent publications was conducted in PubMed and Google Scholar (up to March 2019). Two authors independently selected studies, collected, and analysed data. A total of 1396 abstracts were identified, including 275 oral presentations and 1121 poster presentations. Finally, 606 were published in peer‐reviewed journals, with a publication rate of 43.41%. Abstracts were published earlier if it is from Europe, well funded, presented orally, or with large sample size. The high publication rate of the IADR proceedings supported the impact of IADR annual meetings on paediatric dentistry in the last 10 years. [ABSTRACT FROM AUTHOR]

The scarcity of inexpensive and efficient electrocatalyst for acid water oxidation to molecular oxygen presents the development of nonprecious catalysts for water oxidation a scientific priority. For water splitting, transition-metal dichalcogenides have attracted great interest as advanced catalysts for hydrogen evolution reaction, but there has been no sincere attention to generate significant anodic current density of oxygen evolution reaction (OER) with these materials. Addressing this unmet need, here, the outstanding catalytic performance of MoS2 and TaS2 in OER is demonstrated. Chemically exfoliated 2D thin sheets of MoS2 and TaS2, in both of their 1T and 2H polymorph, have been employed for OER catalysis in acid medium. The best performance for oxygen evolution, which is also comparable to benchmark IrO2, comes out from 1T-MoS2 followed by 1T-TaS2, 2H-MoS2, and 2H-TaS2. Theoretical study reveals that the dominant catalytic activity is on edge sites instead of surface and corroborates the experimental results of polymorphic dependence of electrocatalytic activity. The materials have also shown moderate durability in the harsh acidic medium. The study brings up new set of electrocatalyst for oxygen evolution in acid regime that hitherto has remained largely unrevealed. [ABSTRACT FROM AUTHOR]

Searching for 2D ferromagnetic materials with a high critical temperature, large spin polarization, and controllable magnetization direction is a key challenge for their broad applications in spintronics. Here, through a systematic study on a series of 2D ternary chalcogenides with first‐principles calculations, it is demonstrated that a family of experimentally available 2D CoGa2X4 (X = S, Se, or Te) are half‐metallic ferromagnets, and they exhibit high critical temperature, fully polarized spin state, and strain‐dependent magnetization direction simultaneously. Following the Goodenough–Kanamori rules, the half‐metallic ferromagnetism of CoGa2X4 family is caused by superexchange interaction mediated by CoXCo bonds. The half‐metal gaps are large enough (>0.5 eV) to ensure that the half‐metallicity is stable against the spin flipping at room temperature. Magnetocrystalline anisotropy energy calculations indicate that CoGa2X4 favor easy plane magnetization. Under achievable biaxial tensile strain (2–6%), the magnetization directions of CoGa2X4 can change from in‐plane to out‐of‐plane, providing a route to control the efficiency of spin injection/detection. Further, the critical temperatures Tc of ferromagnetic phase transition for CoGa2X4 are close to room temperature. Belonging to the big family of layered AB2X4 compounds, the proposed CoGa2X4 systems will enrich the available 2D candidates and their heterojunctions for various applications. The CoGa2X4 (X = S, Se, Te) family is predicted to show intrinsic ferromagnetic half‐metallicity with a fully polarized spin state (100% polarization), large half‐metal gap (>0.5 eV), high critical temperature (near room temperature), and strain tunable magnetization direction simultaneously. [ABSTRACT FROM AUTHOR]

In 2D materials, saddle‐points in the electronic structure give rise to diverging density of states, which leads to intriguing physical phenomena useful for applications, including magnetism, superconductivity, charge density wave, as well as enhanced optical absorption. Using first‐principles calculations, monolayer β‐phase group‐IV monochalcogenides (MX, M = Ge or Sn; X = S or Se) are shown to be a new class of 2D materials that possess saddle‐points in both the lowest conduction band and the highest valence band as well as in the joint density of states. Due to the existence of saddle‐points, a remarkable absorption peak within the fundamental gap is found in these materials when the light polarization is along the armchair (y) direction. The properties of saddle‐point excitons can be effectively tuned by both the strain and thickness of these materials. Importantly, the strong optical absorbance induced by saddle‐point exciton absorptions and the appropriate bandgap give ideal power conversion efficiencies as large as 1.11% for monolayer β‐SnSe, significantly higher than reported high‐performance ultrathin solar cells using transition metal dichalcogenides. These results not only open new avenues for exploring novel many‐body physics, but also suggest β‐phase MXs could be promising candidates for future optoelectronic devices. Monolayer β‐phase group‐IV monochalcogenides possess saddle‐points in the joint density of states, which leads to a remarkable absorption peak within the fundamental gap. Accordingly, the power conversion efficiencies for monolayer β‐GeSe and β‐SnSe are significantly higher than reported high‐performance ultrathin solar cells using transition metal dichalcogenides. [ABSTRACT FROM AUTHOR]