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The high power all-solid-state continuous wave single-frequency laser is a significant source for science and application due to good beam quality and low noise. However, the output power of the laser is usually restricted by the harmful thermal lens effect of the solid gain medium. To address this issue, we develop a self-mode-matching compact all-solid-state laser with a symmetrical ring resonator in which four end-pumped Nd:YVO4 laser crystals are used for both laser gain media and mode-matching elements. With this ingenious design, the thermal lens effect of every laser crystal can be controlled and the dynamic of the designed laser including the stability range and the beam waist sizes at crystals can be manipulated only by adjusting the pump power used on each laser gain medium. Under an appropriate combination of pump powers on four crystals, self-mode-matching in a resonator is realized. A stable CW single-frequency at 1064 nm with 140-W power, 102-kHz linewidth, and low intensity noise is obtained. The presented design paves an effective way to further scale-up the output power of a compact laser by employing more pieces of gain media.

Multimode fibers (MMFs) have the potential to carry complex images for endoscopy and related applications, but decoding the complex speckle patterns produced by mode-mixing and modal dispersion in MMFs is a serious challenge. Several groups have recently shown that convolutional neural networks (CNNs) can be trained to perform high-fidelity MMF image reconstruction. We find that a considerably simpler neural network architecture, the single hidden layer dense neural network, performs at least as well as previously-used CNNs in terms of image reconstruction fidelity, and is superior in terms of training time and computing resources required. The trained networks can accurately reconstruct MMF images collected over a week after the cessation of the training set, with the dense network performing as well as the CNN over the entire period., 17 pages, 10 figures

The influence of the pump scheme on the intensity noise of the single-frequency continuous-wave (CW) laser is investigated in this paper, which is implemented in a single-frequency CW Nd:YVO4 1064 nm laser by comparing the traditional 808 nm pumping scheme (TPS) to the direct 888 nm pumping scheme (DPS). Under the conditions that the lasers with TPS and DPS have the same cavity structure and the cavity mirrors, as well as the same operation state including the thermal lens of the laser crystals and the mode-matching between the pump laser mode and the laser cavity mode at the laser crystals, the output power of the laser with DPS is up-to 32.0 W, which is far higher than that of 21.1 W for the laser with TPS. However, the intensity noise of the DPS laser including resonant relaxation oscillation (RRO) frequency of 809 kHz, RRO peak amplitude of 31.6 dB/Hz above the shot noise level (SNL) and the SNL cutoff frequency of 4.2 MHz, respectively, is also higher than that of 606 kHz, 20.4 dB/Hz and 2.4 MHz for the TPS laser. After further analyses, we find that the laser crystal with high doping concentration and long optical length is employed for DPS laser in order to improve the pump laser absorption efficiency, which can simultaneously increase the dipole coupling between the active atoms and the laser cavity, and then results in a high RRO frequency with a large amplitude peak as well as a high SNL cutoff frequency of the laser.

High-power all-solid-state single-frequency continuous-wave (CW) lasers have been applied in basic research such as atomic physics, precision measurement, radar and laser guidance, as well as defense and military fields owing to their intrinsic advantages of high beam quality, low noise, narrow linewidth, and high coherence. With the rapid developments of sciences and technologies, the traditional single-frequency lasers cannot meet the development needs of emerging science and technology such as quantum technology, quantum measurement and quantum optics. After long-term efforts and technical research, a novel theory and technology was proposed and developed for improving the whole performance of high-power all-solid-state single-frequency CW lasers, which was implemented by actively introducing a nonlinear optical loss and controlling the stimulated emission rate (SER) in the laser resonator. As a result, the output power, power and frequency stabilities, tuning range and intensity noise of the single-frequency lasers were effectively enhanced.

We realized a 101 W single-frequency continuous wave (CW) all-solid-state 1064 nm laser by means of mode self-reproduction in this Letter. Two identical laser crystals were placed into a resonator to relax the thermal lens of the laser crystals, and an imaging system was employed to realize cavity mode self-reproduced at the places of the laser crystals. Single-frequency operation of the resonator was realized by employing a new kind of high extinction ratio optical diode based on the terbium scandium aluminum garnet crystal to realize a stable unidirectional operation of the laser, together with introducing a large enough nonlinear loss to the resonator to effectively suppress the multi-mode oscillation and mode hopping of the laser. As a result, a 101 W single-frequency 1064 nm laser in a single-ring resonator was achieved with 42.3% optical efficiency. The measured power stability for 8 h and the beam quality were better than ±0.73% and 1.2, respectively.

In diverse applications employing very thin, single-crystalline semiconductor sheets, including flexible electronics and photonics, energy-storage devices, and solar cells, the impacts of surfaces and interfaces on charge transport need to be understood. The authors study the electrical conductance of very thin Si(001) sheets using a special, sensitive back-gating method, to quantify the influence of H termination on conductance for sheets of different thickness, and confirm that surface states play a dominant role in these conductance properties. Their approach is extensible to other important systems, $e.g.$ $I\phantom{\rule{0}{0ex}}I\phantom{\rule{0}{0ex}}I-V$ semiconductors and transition-metal dichalcogenides.

We report the observation of a large enhancement of the wavelength-dependent photocurrent in ultrathin silicon nanomembranes (SiNM) decorated with colloidal CdSe/ZnS nanocrystal quantum dots (NQDs). Back-gated, field-effect transistor structures based on 75 nm-thick SiNMs are functionalized with self-assembled monolayers (SAMs) preventing surface oxidation and minimizing the surface defect densities. NQDs are drop cast on the active region of the device and the photocurrent is measured as a function of the excitation wavelength across the NQD absorption region. Photocurrent enhancement on the order of several hundred nA's is observed for NQD/SAM/SiNM devices compared to reference SAM/SiNM structures, with the device peak response closely correlated to the NQD absorption peak. We propose light-induced gating of the surface electrostatic potential and forward self-biasing of the FET channel as the two key mechanisms leading to the large photocurrent increase. Our findings open the possibility of employing silicon-nanocrystal hybrid structures for light sensing applications.

Background Alzheimer’s disease is a progressive neurodegenerative disease. Although some of the current treatments offer some symptomatic relief, this disease cannot be cured at present. Electroacupuncture may be effective for Alzheimer’s disease for cognitive function, but the evidence for its effectiveness is still limited. The aim of this study is to evaluate the add-on effect of electroacupuncture to donepezil for improving the cognitive function of Alzheimer’s disease. Methods/design A total of 334 participants with Alzheimer’s disease will be randomly assigned to either an electroacupuncture combined with donepezil group or a donepezil group with a ratio of 1:1. Participants in the electroacupuncture combined with donepezil group will receive electroacupuncture in addition to donepezil for 12 weeks and will keep taking donepezil for the following 24 weeks. Participants in the control group will take donepezil only. The primary outcome is the change from baseline in the total score of the Alzheimer’s Disease Assessment Scale-cognition at week 12. A follow-up will be conducted 24 weeks after the treatment. Discussion We expect to verify the hypothesis that acupuncture in addition to donepezil is better than donepezil in improving the cognitive function of patients with Alzheimer’s disease. This trial has a limitation that participant blinding is impossible. Trial registration Clinical Trials.gov: ID: NCT02305836. Registered on 13 November 2014. Electronic supplementary material The online version of this article (doi:10.1186/s13063-017-2052-y) contains supplementary material, which is available to authorized users.

This is a protocol for a Cochrane Review (Intervention). The objectives are as follows: To assess the efficacy and possible adverse effects of acupuncture for the treatment of post‐stroke upper limb pain.

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The fluorination of graphite/graphite oxide (GO) and their derivatives has been widely investigated for how fluorine interacts with sp2/sp3 carbon; however, the mechanism of this interaction has not yet been elucidated. Fluorination of GO (FGO) at either 10 or 15 psi for 24 h, produced two new absorption bands at ∼743 cm−1 and 482 cm−1, and are attributed to the presence of out-of-plane surface fluorine bonds in FGO (absent in fluorographite – FG). IR studies confirmed the stability of the formed C–F bonds and defect formation due to the introduction of oxyfluorinated species into the graphitic carbon through fluorination of epoxides. Fluorination of GO resulted in ∼4–5 times more fluorine incorporation in bulk as compared to FG. (4.57 vs. 0.8 at.% and 6.64 vs. 1.4 at.% at 10 and 15 psi, respectively). PXRD analyses also showed that the interlayer spacing of FGO expanded in the presence of intercalated C–F species and a defect formation was observed with the evidence of increase of the ID/IG ratio from Raman spectra. To this end, understanding the origin of surface C–F bonds and structural changes in FGO therefore leads to new applications such as implementation of FGO for sensing, nano-electronics and energy storage.

Tourette syndrome (TS) is a neuropsychiatric disorder that affects both children and adults. We searched for randomised controlled trials (RCTs) using acupuncture to treat TS written in English or Chinese without restrictions on publication status. Study selection, data extraction, and assessment of study quality were conducted independently by two reviewers. Meta-analyses were performed using Review Manager (RevMan) 5.3 software from the Cochrane Collaboration. Data were combined with the fixed-effect model based on a heterogeneity test. Results were presented as risk ratios for dichotomous data and mean differences (MDs) for continuous data. This review included 7 RCTs with a total of 564 participants. The combined results showed that acupuncture may have better short-term effect than Western medicine for TS and that acupuncture may be an effective adjuvant therapy in improving the effect of Western medicine on TS, but the evidence is limited because of existing biases. Rigorous high-quality RCTs are needed to verify these findings.

Ultrafast transient pump-probe measurements of thin ${\mathrm{CH}}_{3}{\mathrm{NH}}_{3}{\mathrm{PbI}}_{3}$ perovskite films over a wide spectral range from 350 to 800 nm reveal a family of photoinduced bleach (PB) and absorption (PA) features unequivocally pointing to the fundamentally multiband character of the underlying electronic structure. Excitation pump-energy dependent kinetics of three long-lived PB peaks at 1.65, 2.55, and 3.15 eV along with a broad PA band shows the involvement of band-edge thermalized carriers in all transitions and at least four, possibly more, electronic bands. The evolution of the transient signatures is described in terms of the redistribution of the conserved oscillator strength of the whole system. The multiband perspective opens up different directions for understanding and controlling photoexcitations in hybrid perovskites.

We demonstrate efficient excitonic sensitization of crystalline Si nanomembranes via combined effects of radiative (RET) and nonradiative (NRET) energy transfer from a proximal monolayer of colloidal semiconductor nanocrystals. Ultrathin, 25-300 nm Si films are prepared on top of insulating SiO(2) substrates and grafted with a monolayer of CdSe/ZnS nanocrystals via carboxy-alkyl chain linkers. The wet chemical preparation ensures that Si surfaces are fully passivated with a negligible number of nonradiative surface state defects and that the separation between nanocrystals and Si is tightly controlled. Time-resolved photoluminescence measurements combined with theoretical modeling allow us to quantify individual contributions from RET and NRET. Overall efficiency of ET into Si is estimated to exceed 85% for a short distance of about 4 nm from nanocrystals to the Si surface. Effective and longer-range radiative coupling of nanocrystal's emission to waveguiding modes of Si films is clearly revealed. This demonstration supports the feasibility of an advanced thin-film hybrid solar cell concept that relies on energy transfer between strong light absorbers and adjacent high-mobility Si layers.

Background:Acupuncture is widely used for postherpetic neuralgia (PHN) in China but its effect is unclear. We aim to evaluate the effect and safety of acupuncture for PHN.Methods:The Cochrane Skin Group Trials Register, The Cochrane Central Register of Controlled Trials, MEDLINE, Embase, the

Multiple-layer SOI, in which there are multiple device layers per unit area, is of great interest because it potentially enables fully 3D integration. It also offers the prospect of more complete integration between optics and microelectronics than is possible with purely 2D structures. Here we present a technique for transfer and stacking of multiple single crystal Si nanomembranes with intervening oxide layers, enabling fabrication of multiple-layer SOI. We explain how to overcome transfer challenges, the most important of which is unintentional bonding of nanomembranes to their host substrate during lift-off. We examine the surface roughness of the membranes using atomic force microscopy (AFM). Intriguingly, the intermediate spin-on-glass layers used in this work are rougher than the silicon layers above and below, indicating that membrane transfer can ameliorate roughness introduced by such layers. We have used this process to create multilayer Si/SiO2 heterostructures, i.e., multiple-layer SOI. These structures naturally function as Bragg reflectors, and thus their optical reflectivity can be used as a measure of structure quality. The reflectivity of one, two, and three membrane structures has been measured, and reflectivity above 99% has been achieved for three-layer samples.

The rapid development of perovskite solar cells has focused its attention on defects in perovskites, which are gradually realized to strongly control the device performance. A fundamental understanding is therefore needed for further improvement in this field. Recent efforts have mainly focused on minimizing the surface defects and grain boundaries in thin films. Using time-resolved photoluminescence spectroscopy, we show that bulk defects in perovskite samples prepared using vapor assisted solution process (VASP) play a key role in addition to surface and grain boundary defects. The defect state density of samples prepared at 150 °C (∼10(17) cm(-3)) increases by 5 fold at 175 °C even though the average grains size increases slightly, ruling out grain boundary defects as the main mechanism for the observed differences in PL properties upon annealing. Upon surface passivation using water molecules, the PL intensity and lifetime of samples prepared at 200 °C are only partially improved, remaining significantly lower than those prepared at 150 °C. Thus, the present study indicates that the majority of these defect states observed at elevated growth temperatures originates from bulk defects and underscores the importance to control the formation of bulk defects together with grain boundary and surface defects to further improve the optoelectronic properties of perovskites.

The use of acupuncture for treating Alzheimer disease (AD) has been increasing in frequency over recent years. As more studies are conducted on the use of acupuncture for treating AD, it is necessary to re-assess the effectiveness and safety of this practice. The objective of this study was to assess the effectiveness and safety of acupuncture for treating AD. Central Register of Controlled Trials (CENTRAL), PubMed, MEDLINE, Embase, PsycINFO, Chinese Biomedicine Literature (CBM), Chinese Medical Current Content (CMCC) and China National Knowledge Infrastructure (CNKI) were searched from their inception to June 2014. Randomized controlled trials (RCTs) with AD treated by acupuncture or by acupuncture combined with 1 kind of drugs were included. Two authors extracted data independently. The continuous data were expressed as mean differences (MD) with 95% confidence intervals (CIs). Weighted MD (WMD) was used instead of standardized MD (SMD) when the same scales were used. Adverse reactions related to acupuncture were also investigated. Ten randomized controlled trials with a total of 585 participants were included in the meta-analysis. The combined results of 6 trials showed that acupuncture was better than drugs at improving scores on the Mini Mental State Examination (MMSE) scale (MD 1.05, 95% CI 0.16–1.93). Evidence from the pooled results of 3 trials showed that acupuncture plus donepezil was more effective than donepezil alone at improving the MMSE scale score (MD 2.37, 95% CI 1.53–3.21). Out of 141 clinical trials, 2 trials reported the incidence of adverse reactions related to acupuncture. Seven out of 3416 patients had adverse reactions related to acupuncture during or after treatment; the reactions were described as tolerable and not severe. Acupuncture may be more effective than drugs and may enhance the effect of drugs for treating AD in terms of improving cognitive function. Acupuncture may also be more effective than drugs at improving AD patients’ ability to carry out their daily lives. Moreover, acupuncture is safe for treating people with AD. Protocol registration: PROSPERO CRD42014009619. Protocol published in BMJ-open.

Introduction This systematic review protocol aims to provide a protocol for assessing the safety and effectiveness of acupuncture for the treatment of erectile dysfunction(ED). Previous systematic reviews did not draw convincing conclusions owing to high heterogeneity and few included randomised controlled trials, so it is necessary to reassess the efficacy and safety of acupuncture for ED. Methods and analysis Eight electronic databases will be searched: the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, PubMed, EMBASE, PsycInfo, the Chinese Biomedical Literature Database (CBM), the Chinese Medical Current Content (CMCC) and the China National Knowledge Infrastructure (CNKI). Related Chinese literature will be searched in other Chinese databases. All relevant randomised controlled trials in English or Chinese without any restrictions of publication type will be included. The main outcome measure will be improvements in sexual activity assessed by validated questionnaires. Assessment of risk of bias, data synthesis and subgroup analysis will be carried out using Review Manager 5.3. Ethics and dissemination The results of the systematic review will be disseminated via publication in a peer-reviewed journal and presented at a relevant conference. The data we will use do not include individual patient data, so ethical approval is not required. Trial registration number PROSPERO CRD42014013575.

Introduction This systematic review aims to assess the effectiveness and safety of acupuncture for discomfort in patients during gastroscopy. Methods and analysis Randomised controlled trials will be searched electronically in several databases including OVID MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials (CENTRAL), Chinese Biomedical Literature Database (CBM), Chinese Medical Current Content (CMCC), Chinese Scientific Journal Database (VIP database), Wan-Fang Database and China National Knowledge Infrastructure (CNKI) from their respective founding dates to 30 April 2014. We will also try to find the literature by manually searching conference abstracts and reference lists. The study selection, extraction of data and assessment of study quality will be conducted independently by two researchers. Meta-analysis will be performed using RevMan V.5.2 statistical software. Data will be combined with either the fixed or random effect model based on a heterogeneity test. The results will be presented as a risk ratio for dichotomous data and standardised mean difference for continuous data. Dissemination This systematic review will evaluate the current evidence of acupuncture therapy for discomfort in patients during gastroscopy. The findings will be disseminated through peer-reviewed publication or conference presentations. Trial registration number PROSPERO CRD42014008966.

Introduction The aim of this protocol is to provide the methods used to assess the effectiveness and safety of acupuncture for the treatment of patients with Alzheimer9s disease. Methods and analysis We will search the following electronic databases: The Cochrane Library, PubMed, Medline, Embase, PsycINFO, Chinese Biomedical Literature Database, Chinese Medical Current Contents and China National Knowledge Infrastructure without restriction of language and publication status. Other sources such as Chinese acupuncture journals and the reference list of selected studies will also be searched. After screening the studies, a meta-analysis of randomised controlled trials will be conducted, if possible. Results expressed as risk ratios for dichotomous data and standardised or weighted mean differences for continuous data, will be used for data synthesis. Dissemination The protocol of this systematic review will be disseminated in a peer-reviewed journal and presented at a relevant conference. Trial registration number PROSPERO CRD42014009619

Background The use of acupuncture for stress urinary incontinence is increasing in frequency, especially in Asian area. However, its effectiveness and side effects have not been evaluated. Objectives To assess the effectiveness and side effects of acupuncture for stress urinary incontinence in adults. Search methods We searched the Cochrane Incontinence Group Specialised Register (searched 28 January 2013), EMBASE, AMED, Chinese Biomedical Literature Database (CBM), Chinese Acupuncture Trials Register and China National Knowledge Infrastructure (CNKI) (all searched 20 February 2013). In addition, we searched the reference lists of relevant articles and contacted authors and trialists in the field. Selection criteria Randomised and quasi-randomised controlled trials of acupuncture interventions without other treatments for the management of stress urinary incontinence for adults. Data collection and analysis Two review authors independently assessed eligibility, trial quality and extracted data. We meta-analysed data where appropriate. Main results We identified 17 possibly eligible studies but only one small trial with 60 women met our inclusion criteria. The trial compared acupuncture versus midodrine, a drug for treating hypotension. The risk of bias was high as there was no concealment of randomised allocation, and there was no blinding of assessment of outcome. In addition, it was not possible to blind participants or health providers to the interventions. The statistical methods were not described. More women improved in the acupuncture group (73% with acupuncture versus 33% with midodrine; risk ratio (RR) 2.20, 95% confidence interval (CI) 1.27 to 3.81) but the cure rates were low and not statistically significantly different (13% versus 7%; RR 2.00, 95% CI 0.40 to 10.11). There were adverse events in the drug group only. Authors' conclusions The effect of acupuncture for stress urinary incontinence for adults is uncertain. There is not enough evidence to determine whether acupuncture is more effective than drug treatment.

The electrical properties of nanostructures are extremely sensitive to their surface condition. In very thin two-dimensional crystalline-semiconductor sheets, termed nanomembranes, the influence of the bulk is diminished, and the electrical conductance becomes exquisitely responsive to the structure of the surface and the type and density of defects there. Its understanding therefore requires a precise knowledge of the surface condition. Here we report measurements, using nanomembranes, that demonstrate direct charge transport through the π* band of the clean reconstructed Si(001) surface. We determine the charge carrier mobility in this band. These measurements, performed in ultra-high vacuum to create a truly clean surface, lay the foundation for a quantitative understanding of the role of extended or localized surface states, created by surface structure, defects or adsorbed atoms/molecules, in modifying charge transport through semiconductor nanostructures. As the electrical properties of nanostructures are strongly influenced by their surface, a thorough understanding of the surface properties is desirable. The authors demonstrate the use of charge transport in silicon nanomembranes to perform spectroscopy of the electronic structure of the surface states.

Chemical functionalization of semiconductor surfaces, particularly silicon oxide, has enabled many technologically important applications (e.g., sensing, photovoltaics, and catalysis). For such processes, hydroxyl groups terminating the oxide surface constitute the primary reaction sites. However, their reactivity is often poor, hindering technologically important processes, such as surface phosphonation requiring a lengthy postprocessing annealing step at 140 °C with poor control of the bonding geometry. Using a novel oxide-free surface featuring a well-defined nanopatterned OH coverage, we demonstrate that hydroxyl groups on oxide-free silicon are more reactive than on silicon oxide. On this model surface, we show that a perfectly ordered layer of monodentate phosphonic acid molecules is chemically grafted at room temperature, and explain why it remains completely stable in aqueous environments, in contrast to phosphonates grafted on silicon oxides. This fundamental understanding of chemical activity and surface stability suggests new directions to functionalize silicon for sensors, photovoltaic devices, and nanoelectronics.

Because of the large surface-to-volume ratio, the conductivity of semiconductor nanostructures is very sensitive to surface chemical and structural conditions. Two surface modifications, vacuum hydrogenation (VH) and hydrofluoric acid (HF) cleaning, of silicon nanomembranes (SiNMs) that nominally have the same effect, the hydrogen termination of the surface, are compared. The sheet resistance of the SiNMs, measured by the van der Pauw method, shows that HF etching produces at least an order of magnitude larger drop in sheet resistance than that caused by VH treatment, relative to the very high sheet resistance of samples terminated with native oxide. Re-oxidation rates after these treatments also differ. X-ray photoelectron spectroscopy measurements are consistent with the electrical-conductivity results. We pinpoint the likely cause of the differences. PACS: 73.63.-b, 62.23.Kn, 73.40.Ty

Background Uterine fibroids (UFs) are benign growths within the uterine muscle and are present in 30% of women during their reproductive years. With the exception of hysterectomy, there are no effective medical and surgical treatments for women with uterine fibroids . Acupuncture is an ancient Chinese method which has been used for both the prevention and treatment of diseases for over three thousand years. There are many types of acupuncture used to manage UFs, with body acupuncture being the most commonly used. The literature reporting the benefits or harms of acupuncture for the management of UFs has not yet been systematically reviewed. Objectives To assess the benefits and harms of acupuncture in women with uterine fibroids Search methods The following electronic databases were searched 21st May 2009: the Cochrane Central Register of Controlled Trials (CENTRAL); MEDLINE; EMBASE; AMED; the Menstrual Disorders and Subfertility Group's Specialised Register of Trials; Chinese Biomedical Literature Database (CBM); Traditional Chinese Medical Literature Analysis and Retrieval System (TCMLARS); Chinese Medical Current Contents (CMCC) and China National Knowledge Infrastructure(CNKI). Citation lists, experts in the field and grey literature were also referred to. No restrictions such as language were applied. Selection criteria All randomised controlled trials (RCTs) comparing acupuncture management with placebo acupuncture, no management, Chinese medication, Western medication or other managements of uterine fibroids were considered for inclusion. Acupuncture management included either traditional acupuncture or contemporary acupuncture, regardless of the source of stimulation (for example, body, electro, scalp, elongated, fire, hand, fine needle, moxibustion). Acupuncture management without needling was excluded. Data collection and analysis Two review authors assessed trial risk of bias according to our a priori criteria. No trials were included in this version of the review, therefore no data was collected. Main results No randomized double-blind controlled trials met the inclusion criteria . Authors' conclusions The effectiveness of acupuncture for the management of uterine fibroids remains uncertain. More evidence is required to establish the efficacy and safety of acupuncture for uterine fibroids.There is a continued need for well designed RCTs with long term follow up.

Ultrathin silicon-on-insulator, composed of a crystalline sheet of silicon bounded by native oxide and a buried oxide layer, is extremely resistive because of charge trapping at the interfaces between the sheet of silicon and the oxide. After chemical modification of the top surface with hydrofluoric acid (HF), the sheet resistance drops to values below what is expected based on bulk doping alone. We explain this behavior in terms of surface-induced band structure changes combined with the effective isolation from bulk properties created by crystal thinness.

Reason for Withdrawal Authors have made no progress with this protocol since its publication in 2009. New authors are being sought to take over this title. To view the published versions of this article, please click the 'Other versions' tab.

Transmission electron diffraction is naturally sensitive to the detection of shear-type deformations in single-crystalline structures due to the effective tilting of the lattice planes characteristic of shear, but in general is insensitive to longitudinal phonon propagation. Here, we report on the generation and detection of both transverse and longitudinal coherent acoustic phonons in 33 nm free-standing (001)-oriented single crystalline Si films using femtosecond electron diffraction (FED) to monitor these laser-induced atomic displacements. The mechanism for excitation of the shear mode that leads to coupling to the longitudinal phonon is attributed to the inhomogeneous lateral profile of the optical-pump pulse and the periodic boundary condition imposed by the supporting grid structure. In this application, the constructive interference in the diffraction process makes FED particularly sensitive to the detection of coherent phonon modes and offers an atomic perspective of the dynamics involving collective motions.

Femtosecond electron diffraction studies on (001)-oriented single crystalline Si found that at low excitation, longitudinal and transverse [001] acoustic phonon modes were generated. At ~11% valence excitation, the lattice collapsed non-thermally in

The excitation of a high density of carriers in semiconductors can induce an order-to-disorder phase transition due to changes in the potential-energy landscape of the lattice. We report the first direct resolution of the structural details of this phenomenon in freestanding films of polycrystalline and (001)-oriented crystalline Si, using 200-fs electron pulses. At excitation levels greater than approximately 6% of the valence electron density, the crystalline structure of the lattice is lost in

Introduction Benign prostatic hyperplasia (BPH) is a non-malignant enlargement of the prostate commonly encountered in older men. BPH has been treated with acupuncture inside and outside China, but its effects are uncertain. This review aims to assess the efficacy and safety of acupuncture therapy for BPH. Methods and analysis Seven databases will be searched from their inception: the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, Chinese Biomedical Database, the China National Knowledge Infrastructure, the VIP Database and Wanfang Database. Randomised controlled clinical trials using acupuncture to treat BPH will be included. Outcome measures included urological symptom scores, urodynamic measures and quality-of-life scales. Adverse events will be assessed and reported for safety evaluation. Study selection and data extraction will be performed by two independent reviewers. Quality assessment (assessment of risk of bias) and data synthesis will be implemented using Review Manager (RevMan) software (V.5.2.3). Ethics and dissemination Ethical approval is not necessary because this systematic review will not include specific patient data. Updates will be conducted if there is enough new evidence that may cause any change in review conclusions. Trial registration number PROSPERO CRD42014013645.

Introduction Postherpetic neuralgia (PHN) is one of the most common complications following herpes zoster. Clinical trials indicate that acupuncture could reduce pain and discomfort among patients with PHN. This protocol aims to describe how to accumulate the current evidence on the efficacy and safety of acupuncture for treating PHN. Methods and analysis This systematic review will electronically search multiple databases including the Cochrane Skin Group Trials Register, MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials (CENTRAL), the Chinese Biomedical Literature Database (CBM), the Chinese Medical Current Content (CMCC) and the China National Knowledge Infrastructure (CNKI), and will hand search a list of medical journals as a supplement. Any clinical randomised controlled trials related to acupuncture for treating PHN will be included. Outcomes will include pain intensity, global impression, quality of life, safety and costs. By screening the titles, abstracts and full texts, two reviewers will independently select studies, extract data, and assess study quality. Meta-analysis of randomised controlled trials will be conducted using Revman 5.1 software. The results will be presented as risk ratio for dichotomous data, and standardised or weighted mean difference for continuous data. Ethics and dissemination This systematic review does not need ethical approval because there are no data used in our study that are linked to individual patient data. Also, the findings will be disseminated through a peer-review publication or conference presentation. Trial registration number PROSPERO registration number: CRD42014009555.

The electrical quality of functionalized, oxide-free silicon surfaces is critical for chemical sensing, photovoltaics, and molecular electronics applications. In contrast to Si/SiO2 interfaces, the density of interface states (Dit) cannot be reduced by high temperature annealing because organic layers decompose above 300 °C. While a reasonable Dit is achieved on functionalized atomically flat Si(111) surfaces, it has been challenging to develop successful chemical treatments for the technologically relevant Si(100) surfaces. We demonstrate here that recent advances in the chemical preparation of quasi-atomically-flat, H-terminated Si(100) surfaces lead to a marked suppression of electronic states of functionalized surfaces. Using a non-invasive conductance-voltage method to study functionalized Si(100) surfaces with varying roughness, a Dit as low as 2.5 × 1011 cm−2eV−1 is obtained for the quasi-atomically-flat surfaces, in contrast to >7 × 1011 cm−2eV−1 on atomically rough Si(100) surfaces. The interfaci...

The intrinsic electrical properties of thin organic layers/semiconductor interfaces are challenging to probe because of large tunneling currents through the molecular layer and damage during device fabrication. We present here a method to protect the interface with an Al2O3 layer gently deposited on top using atomic layer deposition. The resulting two-layered gate stack can be characterized with capacitance and conductance measurements. The protected interface shows an inherent high quality with low Dit, less than 2 × 1011 cm−2 eV−1 for n-type Si(111) surface, best measured using mercury probe. The additional procedures required to fabricate MOS capacitors lead to an increase in Dit.