Ultrathin ferroic HfO2-ZrO2 superlattice gate stack for advanced transistors.

With the scaling of lateral dimensions in advanced transistors, an increased gate capacitance is desirable both to retain the control of the gate electrode over the channel and to reduce the operating voltage1. This led to a fundamental change in the gate stack in 2008, the incorporation of high-dielectric-constant HfO2 (ref. 2), which remains the material of choice to date. Here we report HfO2-ZrO2 superlattice heterostructures as a gate stack, stabilized with mixed ferroelectric-antiferroelectric order, directly integrated onto Si transistors, and scaled down to approximately 20 ångströms, the same gate oxide thickness required for high-performance transistors. The overall equivalent oxide thickness in metal-oxide-semiconductor capacitors is equivalent to an effective SiO2 thickness of approximately 6.5 ångströms. Such a low effective oxide thickness and the resulting large capacitance cannot be achieved in conventional HfO2-based high-dielectric-constant gate stacks without scavenging the interfacial SiO2, which has adverse effects on the electron transport and gate leakage current3. Accordingly, our gate stacks, which do not require such scavenging, provide substantially lower leakage current and no mobility degradation. This work demonstrates that ultrathin ferroic HfO2-ZrO2 multilayers, stabilized with competing ferroelectric-antiferroelectric order in the two-nanometre-thickness regime, provide a path towards advanced gate oxide stacks in electronic devices beyond conventional HfO2-based high-dielectric-constant materials.

Evolutionary de Winter pattern: from STEMI to de Winter ECG-a case report.

The de Winter electrocardiography (ECG) pattern is a sign that implies proximal left anterior descending coronary artery occlusion in patients with chest pain. We report a case of a 34-year-old man with a history of smoking who presented to the local emergency department with a 49 min history of chest pain. The first ECG of the patient indicated that ST-segment elevation was noted in the lead V2-V4; 57 min later, a second ECG revealed a typical de Winter syndrome when the patient was transferred to the emergency chest pain centre of our hospital. A percutaneous coronary intervention (PCI) was performed approximately 8 h later because the patient initially refused the PCI. Acute coronary artery angiography showed that the proximal left anterior descending coronary artery was completely occluded. Our case suggests that ST-segment elevation myocardial infarction may evolve in the direction of de Winter, which reflects a coronary thrombus in formation, so the de Winter ECG pattern should not be considered static.

The complete mitochondrial genome of the Black-spot tuskfish (Choerodon schoenleinii).

Choerodon schoenleinii, a critically endangered ocean fish, is also a highly prized commercial fish. In this study, we present the complete mitochondrial genome of C. schoenleinii based on NGS. The length of C. schoenleinii mitochondrial genome is 16,504 bp which consists of 13 protein-coding genes, two rRNA genes, 22 tRNA genes, and a D-loop. The gene order and the composition of mitochondrial genome in C. schoenleinii were similar to other vertebrates. The nucleotide compositions of the light strand are 28.23% of A, 30.51% of C,24.04% of T, and 17.22% of G. Except for ND6 and eight tRNA genes, the rest of mitochondrial genes are encoded on the heavy strand. The construction of phylogenetic trees based on the entire mitochondrial genome sequence of 11 Perciformes species constructed by the NJ method has suggested that the Choerodon schoenleinii has closer relationship to the Chlorurus sordidus, Scarus ruborviolaceus, Scarus forsteri, and Scarus schlegeli, and that they constitute a sister group.

The complete mitochondrial genome of Cheilinus undulates based on high-throughput sequencing technique.

Cheilinus undulatus is a Critically Endangered ocean fish, which is also a higher level predator in coral reef. The complete mitochondrial genome of Cheilinus undulatus has been sequenced by high-throughput sequencing technology. According to the results, the mitochondrial genome of Cheilinus undulatus is 17,184 bp long and consists of 38 protein-coding genes, 2 rRNA genes, 22 tRNA genes and a control region. The nucleotides compositions of the light strand are 27.62% of A, 24.82% of T, 16.66% of G and 30.90% of C. With the exception of ND6 and 8 tRNA genes, all other mitochondrial genes are encoded on the heavy strand. C. undulates mitochondrial genome contains a 568 bp sequences that is a non-coding DNA domain. No homology sequence had been found through BLAST in GenBank. The sequences are probably characteristic species marker of C. undulates.

The complete mitochondrial genome of the Aluterus monoceros.

The complete mitochondrial genome of Aluterus monoceros (A. monoceros) has been sequenced. The mitochondrial genome of A. monoceros is 16,429 bp in length, consisting of 22 tRNA genes, 2 rRNA genes, 13 protein-coding genes and a D-loop region (Gen Bank accession number KP637022). The base A + T of the mitochondrial genome is 63.25%, including 33.16% of A, 30.09% of T and 20.74% of C. Twelve protein-coding genes start with a standard ATG as the initiation codon, expect for the COXI, which begins with GTG. Some of the termination codons are incomplete T or TA, except for the ND1, COXI, ATP8, ND4L1, ND5 and ND6, which stop with TAA. Construction of phylogenetic trees based on the entire mitochondrial genome sequence of 14 Tetrodontiformes species constructed has suggested that A. monoceros has closer relationship with Acreichthys tomentosus and Monacanthus chinensis, and they constitute a sister group.

Microsurgical Resection of Cervical Spinal Cord Arteriovenous Malformations: Report of 6 Cases.

OBJECTIVE: To summarize the experience in microsurgical resection of cervical spinal cord arteriovenous malformation (AVM). METHODS: Six patients undergoing microsurgical resection of cervical intramedullary AVM in the Third Affiliated Hospital of Sun Yat-sen University, China, between March 2005 and March 2015 were reviewed retrospectively, and their clinical manifestations, imaging data, surgical treatment, and results of long-term follow-up were analyzed. RESULTS: Of the 6 patients who underwent AVM resection, 2 had compact AVMs and 4 had diffuse AVMs. All 6 patients were reexamined with spinal magnetic resonance imaging within 48 hours after surgery, and 1 patient was examined with digital subtraction angiography. The average patient age was 40.7 ± 10.4 years (range, 29-60 years). Three patients had chronic onset, of whom 2 developed sensory disturbances and 1 had muscle weakness. The other 3 patients had acute onset, including 1 with sudden quadriplegia, 1 with idiopathic severe headache and altered consciousness, and 1 with idiopathic neck pain. The average duration of follow-up was 48.5 ± 38.9 months (range, 15-119 months). One patient experienced complete recovery, and the other 5 patients showed improvement. No patient exhibited deterioration. CONCLUSION: Microsurgical resection of cervical intramedullary AVMs has obtained satisfactory clinical results. Preoperative magnetic resonance angiography, computed tomography angiography, and digital subtraction angiography are useful for evaluating the angioarchitecture, which is key to the success of surgery. Intraoperative indocyanine green fluorescence angiography is an important aid in the surgical treatment of spinal AVMs.