This letter reports of the fabrication of high-performance p-channel polycrystalline germanium (poly-Ge) thin-film transistors (TFTs) using continuous-wave laser crystallization (CLC). During the CLC ...process, the direction of crystallization matches the direction of laser scanning due to a strong temperature gradient in the melting region. This makes it possible to fabricate high-quality poly-Ge thin films with 1-D longitudinal grains as large as <inline-formula> <tex-math notation="LaTeX">2\,\,\mu \text{m}\,\,\times 20\,\,\mu \text{m} </tex-math> </inline-formula>. We fabricated the proposed p-channel CLC Ge TFTs with channel width of <inline-formula> <tex-math notation="LaTeX">0.7~\mu \text{m} </tex-math> </inline-formula> and a channel length each of <inline-formula> <tex-math notation="LaTeX">0.7~\mu \text{m} </tex-math> </inline-formula>. Consequently, the proposed p-channel CLC Ge TFTs with single-crystal-like channel fabricated on a longitudinal grain with biaxial tensile strain achieved a superior field-effect mobility of 1014.9 cm 2 /V-s.
The strong (>20 nm) wavelength detuning technique has been demonstrated to enhance the modulation speed and high-temperature characteristics (at 85 °C), as well as lower the required driving current ...density performance of oxide-relief 850-nm vertical-cavity surface-emitting lasers (VCSELs) for >40 Gbit/s operation. By increasing the wavelength detuning from 15 to 20 nm, a significant improvement in the electrical-to-optical (E-O) bandwidth (20 to 27 GHz) of the VCSEL can be observed. This detuning design (~20 nm) is incorporated along with a Zn-diffusion structure into our oxide-relief VCSEL with a miniaturized oxide-relief aperture (~3 μm). Highly single-mode, high-speed (26 GHz) operation, and moderate differential resistance (100 Ω) values can be simultaneously achieved. In addition, it is found that devices with a further larger detuning wavelength (>20 nm) and enlarged oxide-relief apertures (~8 μm) can sustain the same maximum E-O bandwidth (26 GHz) as that of a miniaturized (~3 μm) VCSEL, resulting in the lower driving current density (8 versus 18.8 kA/cm 2 ) required for high-speed performance. Excellent transmission performance, which includes an extremely low energy-to-data rate ratio (EDR: 228 fJ/bit; over 100 m OM4 fiber) and record-low driving-current density (8 kA/cm 2 ; 3.5 mA) has been successfully achieved for 41 Gbit/s error-free transmission for these VCSELs.
Metal oxide thin films made from a sol–gel solution process are promising candidates for stable, low cost, and high performance electronic devices. Reducing the thermal budget required for their ...crystallization process can relax the fabrication limitation and expand their possible applications. We show that with the addition of an adequate amount of tetramethylammonium hydroxide (TMAOH) in the precursor solution, the activation energy of the sol–gel reaction can be reduced by about 50%. Using this strategy, not only can the required thermal treatment time and temperature of the sol–gel reaction be significantly reduced but also the quality of the film can be improved. The enhanced reaction rate can be ascribed to the presence of hydroxyl anions, which facilitate the formation of the metal hydroxide and the subsequent metal oxide. Additionally, the strategy developed here can be applied to multiple kinds of metal oxides. By this method, the processing temperature can be lowered by at least 50 °C and the time can be shortened by half for the fabrication of electronic devices such as thin film transistors and photovoltaics. Our results open up a new paradigm to fabricate highly crystalline metal oxide thin films quickly at an energy saving low temperature using the solution process.
Gastrointestinal stromal tumours (GISTs) account for less than 1% of all gastrointestinal tumours. It mainly involves the stomach and small intestines and very rarely involves the ampulla of Vater. ...Endoscopic biopsy and endoscopic ultrasound allow for preoperative tissue diagnosis and local evaluation of the ampullary lesions. We herein report the case of a patient with GIST of the ampulla of Vater presenting with gastrointestinal bleeding and undergoing pancreaticoduodenectomy. The management of ampullary GIST is reviewed.
Background
Laparoscopic liver resection (LLR) of high difficulty score is technically challenging. There is a lack of clinical evidence to support its applicability in terms of the long-term survival ...benefits. This study aims to compare clinical outcomes between LLR and the open liver resection of high difficulty score for hepatocellular carcinoma (HCC).
Materials and Methods
From 2010 to 2020, using Iwate criteria, 424 patients underwent liver resection of high difficulty score by the laparoscopic (
n
= 65) or open (
n
= 359) approach. Propensity score (PS) matching was performed between the two groups. Short-term and long-term outcomes were compared between PS-matched groups. Univariate and multivariate analyses were performed to identify prognostic factors affecting survival.
Results
The laparoscopic group had significantly fewer severe complications (3% vs. 10.8%), and shorter median hospital stays (6 days vs. 8 days) than the open group. Meanwhile, the long-term oncological outcomes were comparable between the two groups, in terms of the tumor recurrence rate (40% vs. 46.1%), the 5-year overall survival rate (75.4% vs. 76.2%), and the 5-year recurrence-free survival rate (50.3% vs. 53.5%). The high preoperative serum alpha-fetoprotein level, multiple tumors, and severe postoperative complications were the independent poor prognostic factors associated with worse overall survival. The surgical approach (Laparoscopic vs. Open) did not influence the survival.
Conclusion
LLR of high difficulty score for selected patients with HCC has better short-term outcomes than the open approach. More importantly, it can achieve similar long-term survival outcomes as the open approach.
In treatment of hepatocellular carcinoma (HCC), both laparoscopic liver resection (LLR) and radiofrequency ablation (RFA) provided similar short-term advantages. However, there was no robust clinical ...trial comparing the efficacy of LLR and RFA especially for small HCC. This study aimed to compare the short-term and long-term outcomes of LLR and RFA for patients with small HCC using a propensity score matching analysis to minimize potential selection bias. Factors affecting survival were then identified with multivariate analysis.
All patients underwent RFA or LLR for small HCC defined as Barcelona Clinic Liver Cancer (BCLC) stage 0 or A, size ≤3 cm, ≤3 nodules on contrast CT scan or MRI with no evidence of macrovascular invasion from April 2005 to August 2020 were included. Propensity score matching was conducted to match patients in the LLR group and RFA group. Prognostic indicators, i.e., age, gender, tumor size, tumor number, Child's grading, albumin, bilirubin, platelet count, international normalized ratio, alpha-fetoprotein level and presence of cirrhosis on imaging were chosen for propensity score calculation. The demographic data, tumor characteristics, operative data, post-operative outcomes and survival data of the two groups were compared. A multivariate analysis based on Cox regression was used to identify factors associated with survival.
Median follow-up was 34 months. LLR and RFA had similar overall survival (91.8%
79.2% at 5-year, P=0.060); while the LLR had a significantly better disease-free survival (49.0%
30.3% at 5-year, P=0.002) and local recurrence-free survival (96.0%
63.7% at 5-year, P<0.001) when compared with the RFA. Multivariate analysis showed that treatment received by patient (LLR
RFA), prothrombin time and platelet counts were significantly associated with disease-free survival. On the other hand, the only factor associated with local recurrence-free survival was the treatment received by patient.
Both RFA and LLR are safe and feasible treatment options for patients with small HCC. LLR should be considered for patients with preserved liver function with a better disease-free survival; while RFA offered a comparable overall survival with less surgical trauma and shorter hospital stay.
In order to investigate the tradeoff between optical spectral width and modulation speed of 850-nm Zn-diffusion vertical-cavity surface-emitting laser (VCSEL) and its influence on the performance of ...discrete multitone (DMT) modulation, two kinds of high-speed VCSEL structures with different cavity lengths (λ/2 and 3λ/2) are studied. By shortening the cavity length to λ/2, allocating the oxide layer in the standing-wave peak, and performing a Zn-diffusion aperture in our VCSEL structure, stable dual mode in the output optical spectra across the full range of bias currents with good high-speed performance (~16-GHz bandwidth) can be achieved. Compared with its multimode reference, it shows far less roll-off with regard to the maximum data rate versus transmission distance over OM4 multimode fibers under forward error correction (FEC) threshold (BER <; 3.8 × 10 -3 ). On the other hand, for the 3λ/2 VCSEL structure, by using the same Zn-diffusion conditions as those of dual-mode counterpart, highly single-mode operation (side-mode suppression ratio> 35 dB) with high available power can be achieved over the full range of bias currents. Although such device shows a smaller 3-dB electrical-to-optical bandwidth (12 versus 16 GHz) than that of the dual-mode one, it exhibits a superior transmission performance by use of DMT modulation format. A record high bit-rate distance product (107.6 Gb/s·km) at nearly 50-Gb/s transmission under FEC threshold (BER<; 3.8 × 10 -3 ) through 2.2-km OM4 fibers has been successfully demonstrated by the use of single-mode VCSEL with optimized structures. In addition, error-free (BER<; 1 × 10 -12 ) transmission at 20.3 Gb/s with bit-rate distance product of 44.66 Gb/s·km has also been demonstrated.
Aluminum nitride (AlN) thin-film materials possess a wide energy gap; thus, they are suitable for use in various optoelectronic devices. In this study, AlN thin films were deposited using radio ...frequency magnetron sputtering with an Al sputtering target and N2 as the reactive gas. The N2 working gas flow rate was varied among 20, 30, and 40 sccm to optimize the AlN thin film growth. The optimal AlN thin film was produced with 40 sccm N2 flow at 500 W under 100% N2 gas and at 600 °C. The films were studied using X-ray diffraction and had (002) phase orientation. X-ray photoelectron spectroscopy was used to determine the atomic content of the optimal film to be Al, 32%; N, 52%; and O, 12% at 100 nm beneath the surface of the thin film. The film was also investigated through atomic force microscopy and had a root mean square roughness of 2.57 nm and a hardness of 76.21 GPa. Finally, in situ continual sputtering was used to produce a gallium nitride (GaN) layer on Si with the AlN thin film as a buffer layer. The AlN thin films investigated in this study have excellent material properties, and the proposed process could be a less expensive method of growing high-quality GaN thin films for various applications in GaN-based power transistors and Si integrated circuits.
Fish in nature are believed to favor their swimming performance by swimming in a school. We investigated numerically the thrust and power consumption of a school of fish with an arrangement of one ...upstream and two downstream. The upstream fish enhances the thrust with an area of high pressure at the heads of the two downstream fish, but the region of low pressure created between the two downstream fish generates a strong suction and is detrimental to the swimming of the upstream fish. The thrust forces increase but the power consumptions of the downstream fish decrease. The downstream fish in this arrangement can avoid the jet flow of the upstream fish and benefit from the counter flow at the verge of the upstream wake. The power-saving mechanism is obvious and sensitive to the longitudinal distance when the fish are in a school within a small lateral distance. The maximum average power consumption in a school is 20% less than not in a school. The mechanisms of thrust enhancement and energy saving in a school of fish interact in manifold ways, and provide insight into the bio-inspired design for arrays of underwater vehicles.
•Numerically examine the thrust enhancement and energy saving of fish school.•The power-saving mechanism is sensitive when the fish school is compact.•The channeling effect between two fish assists the fish motion behind.•The power consumption at the fish head is less than that of swimming solo.•Fish can save up to 20% of power when they swim in a school.
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•Facile strategies that accelerates osseointegration by modifying Ti surfaces.•Functional grafting based on modified silanized-glutaraldehyde fixation surfaces.•Bioactive molecules of ...phosphatidylcholine and COL I grafted functionalization.•Bioactive grafting generated amide groups and improved the hydrophilicity.•Osteogensis gained ALP competition via phosphatidylcholine to COL I in vitro.
This study aims to evaluate sequence-modified Ti surfaces functionalized with silanized glutaraldehyde and further grafted with the active biomolecules of phosphatidylcholine and type I collagen (COL I).
The properties of the functional surfaces were investigated by various surface analysis techniques and characterized their capability in osteogenic cell attachment, differentiation, and mineralization in vitro.
The Ti surfaces grafted with phosphatidylcholine and COL I effectively improved the hydrophilicity. In addition, an effect of COL I concentrations (higher than 2.5μg/mL) do not stimulate subsequent alkaline phosphatase (ALP) activity during osteogenesis in vitro. However, the result is different in phosphatidylcholine, that is, as the concentration of phosphatidylcholine increased enhances subsequent osteogenetic properties. The Ti groups with bioactive molecules affected cell characteristics in vitro in contrast to the controlled Ti group. The proliferation and differentiation levels of osteoprogenetor cells were enhanced and ALP was strongly expressed in the groups grafted with phosphatidylcholine and COL I.
This modification promotes progenitor bone cell adhesion, proliferation, and differentiation and thus drastically improves the success rate for implant modification by accelerating surface osseointegration.
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