Effectiveness of Meditation-based Interventions on Health Problems Caused by COVID-19 Pandemic: Narrative Review.

This article provides a quantitative review of the potential applications of meditation-based interventions (MBIs) in addressing the major health issues arising from the COVID-19 pandemic. The review assesses the effectiveness of MBIs on five prevalent disorders during the pandemic, namely depression, anxiety, stress, insomnia, and long COVID. This is achieved by selecting and scrutinizing seven studies that involve various types of online randomized controlled trials and utilize control group outcomes for effectiveness evaluation. The findings reveal a significant impact of MBIs on overall distress disorder, encompassing symptoms of depression, anxiety, and stress, with effectiveness ranging from 20.5% to 68.8%. The interventions also show moderate effectiveness on insomnia disorder with improvements between 5.2% and 38.5%. However, the effectiveness on long COVID disorder presents a mixed picture, with improvements varying from 0.0% to 71.2% across 13 related symptoms or qualities examined. This review offers compelling evidence supporting the effectiveness of MBIs in alleviating these five prevalent disorders resulting from the COVID-19 pandemic.

Scientific Evidence of Health Benefits by Practicing Mantra Meditation: Narrative Review.

Mantra meditation (MM) is one of the simplest and most effective meditative practices suitable for both novice and skillful meditators. It has attracted a significant number of practitioners for various health benefits or for spiritual inspiration. The scope of this review article focuses on the examination of the health benefits of practicing MM without considering the motivation by spiritual rewarding or cultivation. Through the examination, we attempt to confirm and to add scientific evidence on the benefits of mental and physical health to the practitioners. We review a large number of the recent studies of MM for understanding the mechanism in yielding medical benefits and for analyzing the quantitative evidence of the trial outcomes. The review covers four important areas: stress, anxiety, hypertension, and immunity, with the hope to evoke more studies to refine the current evidence and to encourage more studies in other promising areas. Furthermore, the review gives more attention or discussion on more recent, original, and stronger studies. The discussion can include the strong or weak points of the reviewed studies. The review discovers evidence that MM can provide various degrees of beneficial effects on the four areas considered. Studies with larger participants, superior quality, and a few others are recommended to draw firm conclusions. Several promising research areas and directions are also suggested.

Equivalent Reduction in Greenhouse Gas Emissions by Mahayana Buddhists Practicing Vegetarian Diets.

The equivalent reduction in greenhouse gas emissions (GHGEs) by Mahayana Buddhists with vegetarian diets is quantitatively evaluated. The Buddhists in seven Mahayana-dominated countries or regions, i.e., China, Japan, Vietnam, South Korea, Taiwan, Hong Kong, and Singapore, are studied. Assessments of the vegetarian population among these Mahayana-dominated countries or regions are performed. Correlation formulas based on data from a national survey are developed to quantify the GHGEs of various dietary groups by using the meat consumption as the only required input. To demonstrate its reliability, the prediction from the formulas developed is first compared with the results of a food production-and-consumption study using a different approach. Then, the formulas are used to assess the GHGE reduction due to Mahayana Buddhists with vegetarian diets. The assessment indicates that Mahayana Buddhists with vegetarian diets account for the equivalent GHGE reduction of 48.83 million metric tons of carbon dioxide equivalent, which is a huge amount and is equal to 11.3 or 8.9% of the GHGEs from France or the UK in 2012, respectively.

Removing material using atomic force microscopy with single- and multiple-tip sources.

Atomic force microscopy (AFM) has been an effective material removing tool for fabricating various nanostructures because of its sub-nanometer precision and simplicity in operation. AFM material removing techniques have evolved from a solely mechanical process to one in which the tip can be loaded by additional energy sources, such as thermal, electric, or chemical, to enhance its fabrication abilities. In this paper, these material removing techniques are reviewed with an emphasis on their capabilities and recent progress. The recent hardware and software developments are first presented to provide a general view on the current status of the technology to be assessed. Following an overview of the feasibility and effectiveness of using mechanical scratching for removing various types of soft and hard materials, the processes of a wide range of approaches using multiple tip sources are then assessed with a focus on their principles, versatilities, and potentials for future applications.

Nanopatterning on silicon surface using atomic force microscopy with diamond-like carbon (DLC)-coated Si probe.

Atomic force microscope (AFM) equipped with diamond-like carbon (DLC)-coated Si probe has been used for scratch nanolithography on Si surfaces. The effect of scratch direction, applied tip force, scratch speed, and number of scratches on the size of the scratched geometry has been investigated. The size of the groove differs with scratch direction, which increases with the applied tip force and number of scratches but decreases slightly with scratch speed. Complex nanostructures of arrays of parallel lines and square arrays are further fabricated uniformly and precisely on Si substrates at relatively high scratch speed. DLC-coated Si probe has the potential to be an alternative in AFM-based scratch nanofabrication on hard surfaces.

Profile uniformity of overlapped oxide dots induced by atomic force microscopy.

The technique for assembling a uniform oxide line by overlapping a series of nanosized oxide dots induced by atomic force microscopy is analytically and experimentally investigated. In addition to the normal continuous (static) pulses, the oxide growth rates under various discontinuous (modulated) pluses are studied to quantify the overlapping effect under multiple pulses used by the assembling technique. In the analysis of the assembling technique, the superposition principle is used to predict the assembled profiles and to define the uniformity criteria. Experiments have been performed to demonstrate the analytical prediction, including the threshold or minimum pitch for forming uniform lines, and the onset pitch for the overlapping effect to be considered. Indeed, by following the uniformity criteria developed, uniform and reliable oxide lines can be obtained by overlapping oxide dots.

Charge storage behaviors of Ge nanocrystals embedded in SiO2 for the application in non-volatile memory devices.

Ge nanocrystals distributed in the SiO2 of metal-oxide-semiconductor structure are synthesized by low-energy Ge ion implantation with various energies and doses. Their charge storage behaviors are influenced by both the ion implantation dose and energy. The larger flatband voltage shift achieved by increasing either the implantation dose or energy is explained by the locations and concentration of the charge trapping sites. The smaller charge loss achieved by decreasing the implantation dose or increasing the implantation energy is explained by the co-existence of the charge leakage to the gate electrode and the lateral charge loss to the adjacent Ge nanocrystals.

Nanomachining of permalloy for fabricating nanoscale ferromagnetic structures using atomic force microscopy.

It is well-known that the tip of an Atomic Force Microscope (AFM) can act as a cutting tool for machining various types of materials. In this article, AFM machining experiments have been conducted to investigate the machining characteristics of a nickel-iron thin film material. The influences of the machining parameters on the resulting machined geometries and surfaces are specifically investigated. The machining parameters considered include the normal applied force, number of machining cycles, machining speed, and machining direction. To demonstrate its versatility, the machining technique developed has been applied for fabricating a NiFe based nanostructure required by many ferromagnetic devices. All results indicate that the machined groove size can be well correlated with and precisely controlled by the applied force and the machining cyclic number. The AFM machining technique is indeed simple and predictable for machining nanostructures with specified dimension and controllable precision.

Recent developments in tip-based nanofabrication and its roadmap.

Recent developments of tip-based nanofabrication (TBN) are reviewed. In TBN, a functionalized cantilevered-tip is the common basic apparatus for performing the tasks of nanofabrication. The nanofabrication applications of three major techniques under the TBN family: atomic force microscopy (AFM), dip-pen nanolithography (DPN), and scanning near-field optical microscopy (SNOM), are studied with the focus on their manipulability over the size, orientation, and position of the nanostructures fabricated. The nanostructures made by these techniques are selectively presented in order to illustrate the versatility and advancement of these tip-based techniques. The information reviewed and illustrated is extrapolated to form the basis for the assessment of the needs and challenges facing the TBN community in the future. A preliminary roadmap over the next seven years is then developed. The prospective approaches and focusing areas for future research and development are also discussed.

Nickel nanorods produced by annealing composite oxide films.

Nickel nanorods have been produced by annealing a dense composite film. The nanorods of 45-140 nm in lateral dimensions and 230-1400 nm in longitudinal dimensions were obtained by annealing NiO-YSZ composite films in H2 at 800 degrees C for one hour. The axis of the nanorods at the (220) direction was observed. The dense NiO-YSZ composite film was originally created by co-sputtering Ni and Zr-Y-Ce targets in Ar and O2 environment at 350 degrees C. Reduction of NiOx to Ni nuclei takes place on the surface of the film. The low crystallinity of the original composite film is believed to facilitate the NiO to grow into Ni nanorods on the discrete Ni seeds by diffusion.

Energy shifts of Si oxidation states in the system of Si nanocrystals embedded in SiO2 matrix.

Energy shifts in the Si 2p levels of the five Si oxidation states Sin+ (n = 0, 1, 2, 3, 4) in the system of Si nanocrystals embedded in SiO2 matrix have been determined. The thermal annealing effect on the energy shifts has been studied. The result suggests that the Si nanocrystals and the SiO2 are thermally stable but the annealing can cause some structural deformations such as changes in the bond lengths and bond angles for the suboxides Si2O and SiO. The energy shifts generally show a linear dependence on the oxidation state n, suggesting that the energy shifts could be mainly determined by the nearest-neighbor oxygen atoms. It is shown that the chemical structures of the system are similar to those of the conventional SiO2/Si system in terms of the energy shifts.

Manipulations of atoms and molecules by scanning probe microscopy.

Scanning probe microscopy (SPM), including scanning tunneling microscopy (STM) and atomic force microscopy (AFM), has become a powerful tool in building nanoscale structures required by modern industry. In this article, the use of SPM for the manipulation of atoms and molecules for patterning nanostructures for opt-electronic and biomedical applications is reviewed. The principles and procedures of manipulation using STM and AFM-based technologies are presented with an emphasis on their ability to create a wide variety of nanostructures for different applications. The interaction among the atoms/molecules, surface, and tip are discussed. The approaches for positioning the atom/molecule from and to the desired locations and for precisely controlling its movement are elaborated for each specific manipulation technique. As an AFM-based technique, the dip-pen nanolithography is also included. Finally, concluding remarks on technological improvement and future research is provided.

Nanoscale fabrication by nonconventional approaches.

An overview of three major nonconventional approaches in nanofabrication, scanning probe microscopy lithography, self-assembly, and imprint lithography, is presented. Typically, these nonconventional approaches are emerging technologies based on simple principles with potential cost-effective manufacturability, as compared to those conventional processes that are widely used and highly developed for making microelectronic circuits. Following the introduction of nonconventional technologies and their significances in nanofabrication, the details of each approach are presented. The lithographic applications of scanning probe microscopy, which involves three major variations: scanning tunneling microscopy, atomic force microscopy, and scanning near-field optical microscopy, are first evaluated with emphasis on their abilities in making structures with subnanoscale resolutions. The principles and processes for each technique are presented while their differences are also discussed. For the second approach, self-assembly, which uses a bottom-up fabrication strategy, is reported starting with an introduction of its basic principle. Self-assembly, with and without externally controlled forces for patterning nanoscale structures, is then examined. The associated principles and procedures of key assembling processes are presented. The third one, imprint lithography, is addressed with an emphasis on its recent progress and challenges. The nanolithographic abilities of different techniques developed using the general imprinting principle are examined. Finally, concluding remarks are provided to summarize the major technologies studied and to recommend the scopes for technology improvement and future research.

Recent developments in nanofabrication using focused ion beams.

Focused ion beam (FIB) technology has become increasingly popular in the fabrication of nanoscale structures. In this paper, the recent developments of the FIB technology are examined with emphasis on its ability to fabricate a wide variety of nanostructures. FIB-based nanofabrication involves four major approaches: milling, implantation, ion-induced deposition, and ion-assisted etching of materials; all these approaches are reviewed separately. Following an introduction of the uniqueness and strength of the technology, the ion source and systems used for FIB are presented. The principle and specific techniques underlying each of the four approaches are subsequently studied with emphasis on their abilities of writing structures with nanoscale accuracy. The differences and uniqueness among these techniques are also discussed. Finally, concluding remarks are provided where the strength and weakness of the techniques studied are summarized and the scopes for technological improvement and future research are recommended.

Recent developments in nanofabrication using ion projection lithography.

Ion projection lithography (IPL) is an emerging technology and a major candidate for the next-generation lithography (NGL) designed to complement and supplement current optical lithographic techniques for future chip manufacturing. In this Review, the recent developments of IPL technology are examined with an emphasis on its ability to fabricate a wide variety of nanostructures for the semiconductor industry. Following an introduction of the uniqueness and strength of the technology, the basics of ion-source development and ion-target interactions with and without chemical enhancement are presented. The developments in equipment systems, masks, and resists are subsequently studied. The resolution of printed nanostructures and the corresponding throughput of the current system are assessed for NGL. Finally, concluding remarks are presented to summarize the strengths and weaknesses of the current technology and to suggest the scope for future improvement.