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Nature Communications Dec 2022A highly promising route to scale millions of qubits is to use quantum photonic integrated circuits (PICs), where deterministic photon sources, reconfigurable optical...
A highly promising route to scale millions of qubits is to use quantum photonic integrated circuits (PICs), where deterministic photon sources, reconfigurable optical elements, and single-photon detectors are monolithically integrated on the same silicon chip. The isolation of single-photon emitters, such as the G centers and W centers, in the optical telecommunication O-band, has recently been realized in silicon. In all previous cases, however, single-photon emitters were created uncontrollably in random locations, preventing their scalability. Here, we report the controllable fabrication of single G and W centers in silicon wafers using focused ion beams (FIB) with high probability. We also implement a scalable, broad-beam implantation protocol compatible with the complementary-metal-oxide-semiconductor (CMOS) technology to fabricate single telecom emitters at desired positions on the nanoscale. Our findings unlock a clear and easily exploitable pathway for industrial-scale photonic quantum processors with technology nodes below 100 nm.
PubMed: 36509736
DOI: 10.1038/s41467-022-35051-5 -
Materials (Basel, Switzerland) May 2023Hard and brittle materials such as monocrystalline silicon still occupy an important position in the semiconductor industry, but hard and brittle materials are difficult...
Hard and brittle materials such as monocrystalline silicon still occupy an important position in the semiconductor industry, but hard and brittle materials are difficult to process because of their physical properties. Fixed-diamond abrasive wire-saw cutting is the most widely used method for slicing hard and brittle materials. The diamond abrasive particles on the wire saw wear to a certain extent, which affects the cutting force and wafer surface quality in the cutting process. In this experiment, keeping all the given parameters unchanged, a square silicon ingot is cut repeatedly with a consolidated diamond abrasive wire saw until the wire saw breaks. The experimental results show that the cutting force decreases with the increase in cutting times in the stable grinding stage. The wear of abrasive particles starts at the edges and corners, and the macro failure mode of the wire saw is fatigue fracture. The fluctuation of the wafer surface profile gradually decreases. The surface roughness of wafer is steady during the wear steady stage, and the large damage pits on the wafer surface are reduced in the whole process of cutting.
PubMed: 37241246
DOI: 10.3390/ma16103619 -
Micromachines Jan 2021In situ measurements of sensing signals in space platforms requires that the micro-electro-mechanical system (MEMS) sensors be located directly at the point to be...
In situ measurements of sensing signals in space platforms requires that the micro-electro-mechanical system (MEMS) sensors be located directly at the point to be measured and in contact with the subject to be measured. Traditional radiation-tolerant silicon-based MEMS sensors cannot acquire spatial signals directly. Compared to silicon-based structures, LiNbO single crystalline has wide application prospects in the aerospace field owing to its excellent corrosion resistance, low-temperature resistance and radiation resistance. In our work, 4-inch LiNbO and LiNbO/Cr/Au wafers are fabricated to silicon substrate by means of a polyimide bonding method, respectively. The low-temperature bonding process (≤100 °C) is also useful for heterostructure to avoid wafer fragmentation results from a coefficient of thermal expansion (CTE) mismatch. The hydrophilic polyimide surfaces result from the increasing of -OH groups were acquired based on contact angle and X-ray photoelectron spectroscopy characterizations. A tight and defect-free bonding interface was confirmed by scanning electron microscopy. More importantly, benefiting from low-temperature tolerance and radiation-hardened properties of polyimide material, the bonding strength of the heterostructure based on oxygen plasma activation achieved 6.582 MPa and 3.339 MPa corresponding to room temperature and ultra-low temperature (≈ -263.15 °C), which meets the bonding strength requirements of aerospace applications.
PubMed: 33435433
DOI: 10.3390/mi12010070 -
Turkish Neurosurgery 2014The aim of this study was to a conduct a systematic review of carmustine wafers (Gliadel wafers) for the treatment of glioblastoma multiforme (GBM) to assess the... (Review)
Review
The aim of this study was to a conduct a systematic review of carmustine wafers (Gliadel wafers) for the treatment of glioblastoma multiforme (GBM) to assess the survival benefit and safety of this therapy. The inclusion criteria were 1) prospective or retrospective clinical trial; 2) patients who had undergone resection for primary GBM or first recurrence of GBM with or without carmustine wafer implantation; 3) patients with malignant gliomas that included GBM; 4) outcomes including survival analysis of the GBM population. Six trials met the inclusion criteria; four were randomized, controlled trials and two were retrospective. The trials varied with regard to the type of patients and interventions. In three of the trials, patients with GBM who received carmustine wafers had significantly longer median survival than patients who did not receive wafers. Implantation of carmustine wafers did not significantly improve progression-free survival. Carmustine wafers did not increase adverse effects. This systematic review suggests that carmustine wafers have demonstrated promise as an effective and tolerable treatment in comparison to other treatment strategies in patients with GBM.
Topics: Antineoplastic Agents, Alkylating; Carmustine; Glioblastoma; Humans; Randomized Controlled Trials as Topic; Survival Analysis
PubMed: 25269031
DOI: 10.5137/1019-5149.JTN.8878-13.1 -
RSC Advances Nov 2023In this study, we fabricated four different structures using single crystal silicon wafers for surface-enhanced Raman spectroscopy (SERS) applications. For single...
In this study, we fabricated four different structures using single crystal silicon wafers for surface-enhanced Raman spectroscopy (SERS) applications. For single crystal silicon, different crystal orientations exhibit different physical and chemical properties. In chemical etching, the etching speed of different crystal planes also exhibits significant differences. We first used reactive ion etching (RIE) to process the surface of the substrate, and subsequently used KOH anisotropic wet etching technology to modify the surface of silicon wafers with different crystal orientations and produced four different results. In the RIE stage in an O atmosphere, the (110) silicon wafer formed a hexagonal hole structure, and the (100) silicon wafer formed an inverted pyramid hole structure; however, in the RIE-treated substrates in O and SF atmosphere, the (110) silicon wafer formed a pyramid with a diamond-shaped base, and the (100) silicon wafer showed a columnar structure with a "straw hat" at the top. The formation mechanisms of these four structures were elucidated. We also performed structure-related SERS characterizations of the four different structures and compared their performance differences.
PubMed: 38020018
DOI: 10.1039/d3ra04797k -
Heliyon Nov 2019This study was designed to determine the effects of a food thickener and deglutition aid jelly for oral administration, jelly wafer, on the pharmacokinetics of...
This study was designed to determine the effects of a food thickener and deglutition aid jelly for oral administration, jelly wafer, on the pharmacokinetics of levofloxacin orally disintegrating tablets. With an increase in immersion time, the disintegration time of levofloxacin orally disintegrating tablets immersed in food thickener was prolonged, whereas that of the tablets immersed in jelly wafer was shortened. The dissolution behavior of non-immersed levofloxacin orally disintegrating tablets was not similar to that of tablets immersed in food thickener, but was similar to that of tablets immersed in jelly wafer. The time to reach the maximum systemic levofloxacin concentration was the same for non-immersed orally disintegrating tablets and tablets immersed in food thickener and jelly wafer. Moreover, there was no significant difference in the maximum concentration after administration between non-immersed orally disintegrating tablets and tablets immersed in food thickener or jelly wafer. These findings suggest that drugs with a high bioavailability, such as levofloxacin, enter the systemic circulation even when administered with a food thickener or jelly wafer.
PubMed: 31844704
DOI: 10.1016/j.heliyon.2019.e02764 -
Scientific Reports Feb 2023To improve the manufacturing process of GaN wafers, inexpensive wafer screening techniques are required to both provide feedback to the manufacturing process and prevent...
To improve the manufacturing process of GaN wafers, inexpensive wafer screening techniques are required to both provide feedback to the manufacturing process and prevent fabrication on low quality or defective wafers, thus reducing costs resulting from wasted processing effort. Many of the wafer scale characterization techniques-including optical profilometry-produce difficult to interpret results, while models using classical programming techniques require laborious translation of the human-generated data interpretation methodology. Alternatively, machine learning techniques are effective at producing such models if sufficient data is available. For this research project, we fabricated over 6000 vertical PiN GaN diodes across 10 wafers. Using low resolution wafer scale optical profilometry data taken before fabrication, we successfully trained four different machine learning models. All models predict device pass and fail with 70-75% accuracy, and the wafer yield can be predicted within 15% error on the majority of wafers.
PubMed: 36849490
DOI: 10.1038/s41598-023-29107-9 -
Neuro-oncology Jan 20153-bromopyruvate (3-BrPA) and dichloroacetate (DCA) are inhibitors of cancer-cell specific aerobic glycolysis. Their application in glioma is limited by 3-BrPA's...
BACKGROUND
3-bromopyruvate (3-BrPA) and dichloroacetate (DCA) are inhibitors of cancer-cell specific aerobic glycolysis. Their application in glioma is limited by 3-BrPA's inability to cross the blood-brain-barrier and DCA's dose-limiting toxicity. The safety and efficacy of intracranial delivery of these compounds were assessed.
METHODS
Cytotoxicity of 3-BrPA and DCA were analyzed in U87, 9L, and F98 glioma cell lines. 3-BrPA and DCA were incorporated into biodegradable pCPP:SA wafers, and the maximally tolerated dose was determined in F344 rats. Efficacies of the intracranial 3-BrPA wafer and DCA wafer were assessed in a rodent allograft model of high-grade glioma, both as a monotherapy and in combination with temozolomide (TMZ) and radiation therapy (XRT).
RESULTS
3-BrPA and DCA were found to have similar IC50 values across the 3 glioma cell lines. 5% 3-BrPA wafer-treated animals had significantly increased survival compared with controls (P = .0027). The median survival of rats with the 50% DCA wafer increased significantly compared with both the oral DCA group (P = .050) and the controls (P = .02). Rats implanted on day 0 with a 5% 3-BrPA wafer in combination with TMZ had significantly increased survival over either therapy alone. No statistical difference in survival was noted when the wafers were added to the combination therapy of TMZ and XRT, but the 5% 3-BrPA wafer given on day 0 in combination with TMZ and XRT resulted in long-term survivorship of 30%.
CONCLUSION
Intracranial delivery of 3-BrPA and DCA polymer was safe and significantly increased survival in an animal model of glioma, a potential novel therapeutic approach. The combination of intracranial 3-BrPA and TMZ provided a synergistic effect.
Topics: Absorbable Implants; Animals; Antineoplastic Agents; Antineoplastic Agents, Alkylating; Brain Neoplasms; Cell Line, Tumor; Cell Proliferation; Combined Modality Therapy; Dacarbazine; Dichloroacetic Acid; Drug Administration Routes; Drug Combinations; Drug Delivery Systems; Female; Glioblastoma; Glycolysis; Humans; Kaplan-Meier Estimate; Polymers; Pyruvates; Rats; Rats, Inbred F344; Temozolomide
PubMed: 25053853
DOI: 10.1093/neuonc/nou143 -
Biomedicine & Pharmacotherapy =... Jan 2021Despite the role of curcumin in controlling inflammation, angiogenesis, and cancer in human cells, its therapeutic use is limited. The reasons are quick metabolic...
Despite the role of curcumin in controlling inflammation, angiogenesis, and cancer in human cells, its therapeutic use is limited. The reasons are quick metabolic breakdown, low aqueous solubility, and bioavailability. This study describes the advantages of clinical-grade curcumin-incorporated fibrin matrix either in lyophilized off-the-shelf wafer or injectable hydrogel forms, as a biodegradable local delivery system. To produce the curcumin-fibrin wafer, used clinical-grade fibrin sealant in a modified composition. To fabricate wafer, we premixed the curcumin with either fibrinogen or thrombin, before clotting into a hydrogel. Sustained release of active curcumin from fibrin wafer, suspended in culture medium at 37 °C lasted for seven days. Upon premixing albumin with thrombin and subsequently adding curcumin into the mixture improved the loading concentration and stability. Dose- and time-dependent apoptotic function of curcumin on cancer cell lines upon release from fibrin wafer, were demonstrated in vitro. In vivo immuno-modulation and a nontoxic response to curcumin released from fibrin into the peritoneal cavity of mice were established. The cytotoxic effect of released curcumin was demonstrated; showing both a preventive and therapeutic role against tumor growth. In vivo studies used Dalton's Lymphoma Ascites (DLA) mice model. Both implanted fibrin wafer and injected hydrogel can breakdown by a physiological process and get cleared by the fibrinolytic mechanism. The lyophilized fibrin wafer could function as a hemostat, adhere to surgical cancer tissues, and arrest bleeding. The potential of curcumin in preventing solid tumor metastasis may be explored upon the sustained delivery of the molecule from the fibrin wafer.
Topics: A549 Cells; Animals; Antineoplastic Agents, Phytogenic; Apoptosis; Ascites; Cell Proliferation; Curcumin; Delayed-Action Preparations; Drug Carriers; Drug Compounding; Drug Liberation; Female; Fibrin; Humans; Hydrogels; Lymphoma; Mice; PC-3 Cells
PubMed: 33221650
DOI: 10.1016/j.biopha.2020.110967 -
Micromachines Dec 2022Corrosive and toxic solutions are normally employed to polish sapphire wafers, which easily cause environmental pollution. Applying green polishing techniques to obtain...
Corrosive and toxic solutions are normally employed to polish sapphire wafers, which easily cause environmental pollution. Applying green polishing techniques to obtain an ultrasmooth sapphire surface that is scratch-free and has low damage at high polishing efficiency is a great challenge. In this paper, novel diamond/SiO composite abrasives were successfully synthesized by a simplified sol-gel strategy. The prepared composite abrasives were used in the semi-fixed polishing technology of sapphire wafers, where the polishing slurry contains only deionized water and no other chemicals during the whole polishing process, effectively avoiding environmental pollution. The experimental results showed that diamond/SiO composite abrasives exhibited excellent polishing performance, along with a 27.2% decrease in surface roughness, and the material removal rate was increased by more than 8.8% compared with pure diamond. Furthermore, through characterizations of polished sapphire surfaces and wear debris, the chemical action mechanism of composite abrasives was investigated, which confirmed the solid-state reaction between the SiO shell and the sapphire surface. Finally, applying the elastic-plastic contact model revealed that the reduction of indentation depth and the synergistic effect of chemical corrosion and mechanical removal are the keys to improving polishing performance.
PubMed: 36557459
DOI: 10.3390/mi13122160