Phosphoglycerate mutase 5 aggravates alcoholic liver disease through disrupting VDAC-1-dependent mitochondrial integrity.

Alcoholic liver disease (ALD) poses a substantial global health challenge, with its pathogenesis deeply rooted in mitochondrial dysfunction. Our study explores the pivotal roles of Phosphoglycerate mutase family member 5 (Pgam5) and Voltage-Dependent Anion Channel 1 (VDAC1) in the progression of ALD, providing novel insights into their interplay and impact on mitochondrial integrity. We demonstrate that Pgam5 silencing preserves hepatocyte viability and attenuates ethanol-induced apoptosis, underscoring its detrimental role in exacerbating hepatocyte dysfunction. Pgam5's influence extends to the regulation of VDAC1 oligomerization, a key process in mitochondrial permeability transition pore (mPTP) opening, mitochondrial swelling, and apoptosis initiation. Notably, the inhibition of VDAC1 oligomerization through Pgam5 silencing or pharmacological intervention (VBIT-12) significantly preserves mitochondrial function, evident in the maintenance of mitochondrial membrane potential and reduced reactive oxygen species (ROS) production. In vivo experiments using hepatocyte-specific Pgam5 knockout (Pgam5hKO) and control mice reveal that Pgam5 deficiency mitigates ethanol-induced liver histopathology, inflammation, lipid peroxidation, and metabolic disorder, further supporting its role in ALD progression. Our findings highlight the critical involvement of Pgam5 and VDAC1 in mitochondrial dysfunction in ALD, suggesting potential therapeutic targets. While promising, these findings necessitate further research, including human studies, to validate their clinical applicability and explore broader implications in liver diseases. Overall, our study provides a significant advancement in understanding ALD pathophysiology, paving the way for novel therapeutic strategies targeting mitochondrial pathways in ALD.

Efficacy and safety of Argatroban in patients with acute ischemic stroke: a systematic review and meta-analysis.

Objective: Argatroban is a highly promising drug for the treatment of acute ischemic stroke (AIS), but there is currently insufficient strong evidence regarding the efficacy and safety of using Argatroban in the treatment of AIS. Therefore, we conducted a systematic review and meta-analysis to evaluate the effectiveness and safety of Argatroban in the treatment of AIS. Methods: Articles on PubMed, Embase and the Cochrane Library databases were searched from these websites' inceptions to 2th February 2023. Randomized controlled trials and observational studies on Argatroban therapy for acute ischemic stroke were included. Meta-analyses were conducted using a random-effects model. Results: Fourteen studies involving 10,315 patients were included in the meta-analysis. The results showed a significant reduction in the rate of early neurological deterioration (END) in the Argatroban group compared with the control group (OR = 0.47, 95% CI: 0.31-0.73, I2 = 15.17%). The rates of adverse events were no significant difference between the two groups (ICH: OR = 1.02, 95% CI: 0.68-1.51, I2 = 0.00%; major extracranial bleeding: OR = 1.22, 95% CI: 1.01-1.48, I2 = 0.00%; mortality: OR = 1.16, 95% CI: 0.84-1.59, I2 = 0.00%). However, the rates of mRS score of 0-1 (OR = 1.38, 95% CI: 0.71-2.67, I2 = 77.56%) and mRS score of 0-2 (OR = 1.18, 95% CI: 0.98-1.42, I2 = 0.00%) during the 90 days did not significantly improved in the Argatroban group. Subgroup analyses showed that the rate of END (OR = 0.41, 95% CI: 0.26-0.65, I2 = 2.77%) and mRS score of 0-2 (OR = 1.38, 95% CI: 1.06-1.81, I2 = 0.00%) had significantly improved when the intervention group adopted Argatroban plus Antiplatelet. Conclusion: Argatroban can improve neurological deterioration, with a low incidence of adverse events such as bleeding and death, and general analysis showed no improvement in mRS. However, subgroup analysis suggests that compared to mono-antiplatelet therapy, combination therapy of Argatroban combined with antiplatelet therapy significantly reduced the incidence of END and improved mRS scores. After using Argatroban, there was no increase in the risk and mortality of intracranial hemorrhage and other bleeding sites.

Efficient current-induced spin torques and field-free magnetization switching in a room-temperature van der Waals magnet.

The discovery of magnetism in van der Waals (vdW) materials has established unique building blocks for the research of emergent spintronic phenomena. In particular, owing to their intrinsically clean surface without dangling bonds, the vdW magnets hold the potential to construct a superior interface that allows for efficient electrical manipulation of magnetism. Despite several attempts in this direction, it usually requires a cryogenic condition and the assistance of external magnetic fields, which is detrimental to the real application. Here, we fabricate heterostructures based on Fe3GaTe2 flakes that have room-temperature ferromagnetism with excellent perpendicular magnetic anisotropy. The current-driven nonreciprocal modulation of coercive fields reveals a high spin-torque efficiency in the Fe3GaTe2/Pt heterostructures, which further leads to a full magnetization switching by current. Moreover, we demonstrate the field-free magnetization switching resulting from out-of-plane polarized spin currents by asymmetric geometry design. Our work could expedite the development of efficient vdW spintronic logic, memory, and neuromorphic computing devices.

Radiation-Hardened and Flexible Pb(Zr0.53Ti0.47)O3 Piezoelectric Sensor for Structural Health Monitoring.

Piezoelectric sensors are excellent damage detectors that can be applied to structural health monitoring (SHM). SHM for complex structures of aerospace vehicles working in harsh conditions is frequently required, posing challenging requirements for a sensor's flexibility, radiation hardness, and high-temperature tolerance. Here, we fabricate a flexible and lightweight Pb(Zr0.53Ti0.47)O3 piezoelectric film on flexible KMg3(AlSi3O10)F2 substrate via van der Waals (vdW) heteroepitaxy, endowing it with robust ferroelectric and piezoelectric properties under low energy-high flux protons (LE-HFPs) radiation (1015 p/cm2). More importantly, the Pb(Zr0.53Ti0.47)O3 film sensor maintains highly stable damage monitoring sensitivity on an aluminum plate under harsh conditions of LE-HFPs radiation (1015 p/cm2, flat structure), high temperature (175 °C, flat structure), and mechanical fatigue (bending 105 cycles under a radius of 5 mm, curved structure). All these superior qualities are suggested to result from the outstanding film crystal quality due to vdW epitaxy. The flexible and lightweight Pb(Zr0.53Ti0.47)O3 film sensor demonstrated in this work provides an ideal candidate for real-time SHM of aerospace vehicles with flat and complex curve-like structures working in harsh aerospace environments.

Effect of Ultrasonic Treatment on Structure, Antibacterial Activity of Sugarcane Leaf Polysaccharides.

This study investigated the impact of ultrasonic extraction (UE) on the structure and in vitro antibacterial activity of polysaccharides from sugarcane leaves (SLW). Native sugarcane leaf polysaccharides were treated with ultrasound (480 W) for 3 h to yield sugarcane leaf polysaccharides (SLU). Compared to SLW (33.59 kDa), the molecular weight of SLU (13.08 kDa) was significantly decreased, while the monosaccharide composition of SLU was unchanged. The results of SEM and XRD indicated that UE significantly changed the surface morphology of SLW and destroyed its inner crystalline structure. In vitro experiments showed that SLU had stronger antibacterial activity. These findings revealed that UE treatment could alter the tertiary structure of SLW but had no impact on its primary structure. Furthermore, the antibacterial activity of SLW could be greatly enhanced after UE treatment. As a bioactive additive, SLU has great application potential in functional foods, cosmetics, and pharmaceuticals.

Efficacy of ultrasound-guided percutaneous transhepatic biliary drainage for acute obstructive suppurative cholangitis combined with septic shock.

OBJECTIVES: This study aimed to investigate the efficacy of ultrasound-guided Percutaneous Transhepatic Biliary Drainage (PTCD) for the treatment of Acute Obstructive Suppurative Cholangitis (AOSC) combined with septic shock due to choledocholithiasis, and its effect on inflammatory factors. METHODS: Clinical data of 86 patients with AOSC and septic shock admitted to our hospital between January 2019 and May 2021 were retrospectively analyzed and grouped according to different treatment methods. Among them, 43 patients who underwent Endoscopic Retrograde Cholangiopancreatography (ERCP) and Endoscopic Nasobiliary Drainage (ENBD) were included in the Control Group (CNG), and 43 patients who underwent ultrasound-guided PTCD were included in the Study Group (SG). RESULTS: The total effective rate in the SG (88.37%) was higher than that in the CNG (69.77%) (p < 0.05); after surgery, the serum inflammatory factors PCT, IL-6, TNF-α, CRP levels, liver function indicators such as TBIL, DBIL, AST, ALT levels, and stress response indicators including NPY, PGE2, 5-HT levels were reduced, and were lower in the SG than in the CNG (p < 0.05); postoperatively, CD3+, CD4+, and CD4+/CD8+ levels in the CNG were significantly lower than those before surgery (p < 0.05); Postoperatively, CD3+, CD4+, and CD4+/CD8+ levels in the SG were significantly higher than those in the CNG (p < 0.05); and the complication rate in the SG (6.98%) was lower than that in the CNG (25.58%) (p < 0.05). CONCLUSIONS: Ultrasound-guided PTCD for AOSC combined with septic shock can facilitate the recovery of liver and immune functions with a low complication rate.

Magnetotransport property of oxygen-annealed Fe1+yTe thin films.

Fe-based superconductors are one of the current research focuses. FeTe is unique in the series of FeSe1-xTex, since it is nonsuperconducting near the FeTe side in the phase diagram in contrast to the presence of superconductivity in other region. However, FeTe thin films become superconducting after oxygen annealing and the mechanism remains elusive. Here, we report the temperature dependences of resistivity, Hall effect and magnetoresistance (MR) of a series of FeTe thin films with different amounts of excess Fe and oxygen. These properties show dramatic changes with excess Fe and oxygen incorporation. We found the Hall coefficients are positive for the oxygen-annealed samples, in contrast to the transition from positive to negative below 50 K for the vacuum-annealed samples. For all samples, both the resistivity and Hall coefficient show a dramatic drop, respectively, at around 50 K-75 K, implying coexistence of superconductivity and antiferromagnetic order for the oxygen-annealed samples. The vacuum-annealed samples show both positive and negative values of MR depending on temperature, while negative MR dominates for the oxygen-annealed samples. We also found that oxygen annealing reduces the excess Fe in FeTe, which has been neglected before. The results are discussed in terms of several contributions, and a comparison is made between the oxygen-annealed FeTe thin films and FeSe1-xTex. This work is helpful for shedding light on the understanding of oxygen-annealed FeTe thin films.

Efficacy of ultrasound-guided percutaneous transhepatic biliary drainage for acute obstructive suppurative cholangitis combined with septic shock

Abstract Objectives This study aimed to investigate the efficacy of ultrasound-guided Percutaneous Transhepatic Biliary Drainage (PTCD) for the treatment of Acute Obstructive Suppurative Cholangitis (AOSC) combined with septic shock due to choledocholithiasis, and its effect on inflammatory factors. Methods Clinical data of 86 patients with AOSC and septic shock admitted to our hospital between January 2019 and May 2021 were retrospectively analyzed and grouped according to different treatment methods. Among them, 43 patients who underwent Endoscopic Retrograde Cholangiopancreatography (ERCP) and Endoscopic Nasobiliary Drainage (ENBD) were included in the Control Group (CNG), and 43 patients who underwent ultrasound-guided PTCD were included in the Study Group (SG). Results The total effective rate in the SG (88.37%) was higher than that in the CNG (69.77%) (p <0.05); after surgery, the serum inflammatory factors PCT, IL-6, TNF-α, CRP levels, liver function indicators such as TBIL, DBIL, AST, ALT levels, and stress response indicators including NPY, PGE2, 5-HT levels were reduced, and were lower in the SG than in the CNG (p <0.05); postoperatively, CD3+, CD4+, and CD4+/CD8+ levels in the CNG were significantly lower than those before surgery (p <0.05); Postoperatively, CD3+, CD4+, and CD4+/CD8+ levels in the SG were significantly higher than those in the CNG (p <0.05); and the complication rate in the SG (6.98%) was lower than that in the CNG (25.58%) (p <0.05). Conclusions Ultrasound-guided PTCD for AOSC combined with septic shock can facilitate the recovery of liver and immune functions with a low complication rate.

A single solvating benzene molecule decouples the mixed-valence complex through intermolecular orbital interactions.

Characterization of covalency of intermolecular interactions in the van der Waals distance limit remains challenging because the interactions between molecules are weak, dynamic, and not measurable. Herein, we approach this issue in a series of supramolecular mixed-valence (MV) donor(D)-bridge(B)-acceptor(A) systems consisting of two bridged Mo2 units with a C6H6 molecule encapsulated, as characterized by the X-ray crystal structures. Comparative analysis of the intervalence charge transfer spectra in benzene and dichloromethane substantiates the strong electronic decoupling effect of the solvating C6H6 molecule that breaks down the dielectric solvation theory. Ab initio and DFT calculations unravel that the intermolecular orbital overlaps between the complex bridge and the C6H6 molecule alter the electronic states of the D-B-A molecule through intermolecular nuclear dynamics. This work exemplifies that site-specific intermolecular interaction can be exploited to control the chemical property of supramolecular systems and to elucidate the functionalities of side-chains in biological systems.

Clinical, neuroimaging and gene mutation characteristics of McLeod syndrome and literature review / 中华神经科杂志

Objective:To study the characteristics of clinical, laboratory, imaging, genetic and differential diagnosis of McLeod syndrome.Methods:The clinical characteristics of 2 cases of McLeod syndrome confirmed by gene detection in Qilu Hospital (Qingdao) on June 27, 2018 and in Qilu Hospital of Shandong University on September 11, 2019 were analyzed retrospectively. And the characteristics of patients of McLeod syndrome reported in China were analyzed in combination with literature review.Results:Both of the 2 patients were adult male, aged 57 and 61 years, respectively, with a slowly progressive course, beginning with gradually involuntary movement of trunk and extremities, involving involuntary biting of the tongue and dysphagia. Two patients had mild cognitive impairment; one patient had emotional agitation. Imaging study showed atrophy of caput nuclei caudate. Neuroelectrophysiological examination of case 1 showed sensory axon neuropathy in both upper limbs with severe damage to the left ulnar nerve. Creatine kinase (CK) was mildly elevated in 2 patients. The peripheral blood smear of 1 patient showed increased acanthocytes, accounting for 13%, the other patient showed no increased acanthocyte. McLeod syndrome related gene was tested in the 2 patients, case 1 with deletion mutation of exon 2 of XK gene, and case 2 with hemizygotic mutation of XK gene c.898delC p.L300 *. Conclusions:The clinical manifestations of McLeod syndrome are various and the differential diagnosis is crucial. For elderly male with cephalic facial chorea, elevated CK level and neuromuscular diseases, the possibility of McLeod syndrome should be screened.

Crossover between the adiabatic and nonadiabatic electron transfer limits in the Landau-Zener model.

The semiclassical models of nonadiabatic transition were proposed first by Landau and Zener in 1932, and have been widely used in the study of electron transfer (ET); however, experimental demonstration of the Landau-Zener formula remains challenging to observe. Herein, employing the Hush-Marcus theory, thermal ET in mixed-valence complexes {[Mo2]-(ph)n-[Mo2]}+ (n = 1-3) has been investigated, spanning the nonadiabatic throughout the adiabatic limit, by analysis of the intervalence transition absorbances. Evidently, the Landau-Zener formula is valid in the adiabatic regime in a broader range of conditions than the theoretical limitation known as the narrow avoided-crossing. The intermediate system is identified with an overall transition probability (κel) of ∼0.5, which is contributed by the single and the first multiple passage. This study shows that in the intermediate regime, the ET kinetic results derived from the adiabatic and nonadiabatic formalisms are nearly identical, in accordance with the Landau-Zener model. The obtained insights help to understand and control the ET processes in biological and chemical systems.

Percutaneous biliary stent combined with brachytherapy using 125I seeds for treatment of unresectable malignant obstructive jaundice: A meta-analysis.

BACKGROUND: Malignant obstructive jaundice (MOJ) is a common pathologic manifestation of malignant biliary obstruction. Recently, several clinical trials have explored the clinical effectiveness of intraluminal 125I seed-based brachytherapy for MOJ patients, and various outcomes have been reported. AIM: To assess the efficacy and safety of percutaneous biliary stents with 125I seeds compared to conventional metal stents in patients with unresectable MOJ. METHODS: A systematic search of English-language databases (PubMed, Embase, Cochrane Library, and Web of Science) was performed to identify studies published prior to June 2020 that compared stents with or without 125I seeds in the treatment of unresectable MOJ. The outcomes analyzed included primary outcomes (stent patency and overall survival) and secondary outcomes (complications and liver function parameters). RESULTS: Six randomized controlled trials and four retrospective studies involving 875 patients were eligible for the analysis. Of the 875 included patients, 404 were treated with 125I seed stents, while 471 were treated with conventional stents. Unadjusted pooled analysis demonstrated that compared to conventional stents, 125I seed stents extended the stent patency time [hazard ratio (HR) = 0.36, 95% confidence interval (CI) = 0.28-0.45, P < 0.0001] and overall survival period (HR = 0.52, 95%CI = 0.42-0.64, P < 0.00001). Subgroup analyses based on the type of 125I seed stent and type of study design showed consistent results. However, there were no significant differences in the occurrence of total complications [odds ratio (OR) = 1.12, 95%CI = 0.75-1.67, P = 0.57], hemobilia (OR = 1.02, 95%CI = 0.45-2.3, P = 0.96), pancreatitis (OR = 1.79, 95%CI = 0.42-7.53, P = 0.43), cholangitis (OR = 1.13, 95%CI = 0.60-2.13, P = 0.71), or pain (OR = 0.67, 95%CI = 0.22-2, P = 0.47). In addition, there were no reductions in the levels of serum indices, including total bilirubin [mean difference (MD) = 10.96, 95%CI = -3.56-25.49, P = 0.14], direct bilirubin (MD = 7.37, 95%CI = -9.76-24.5, P = 0.4), alanine aminotransferase (MD = 7.52, 95%CI = -0.71-15.74, P = 0.07), and aspartate aminotransferase (MD = -4.77, 95%CI = -19.98-10.44, P = 0.54), after treatment. Publication bias was detected regarding the outcome overall survival; however, the conclusions were not changed after the adjustment. CONCLUSION: Placement of stents combined with brachytherapy using 125I seeds contributes to a longer stent patency and higher overall survival than placement of conventional stents without extra complications or severe liver damage. Thus, it can be considered an effective and safe treatment for unresectable MOJ.

Clinical analysis of type Ⅱ Alexander disease and literature review / 中华神经科杂志

Objective:To analyze the clinical features, imaging findings and gene test of patients with type Ⅱ Alexander disease.Methods:All the clinical data of three cases with type Ⅱ Alexander disease from August 2018 to June 2020 in the Department of Neurology, Qilu Hospital of Shandong University (Qingdao) and Qilu Hospital of Shandong University were collected, and their clinical and imaging findings were analyzed retrospectively.Results:All the three patients were middle aged and old men with a chronic progressive course, beginning with weakness of one or both lower limbs, followed by dizziness, dysarthria, dysphagia, sphincteral disturbances, constipation and orthostatic hypotension. Three patients all experienced misdiagnosis (hydrarthrosis, cerebral vascular disease, alcoholism, respectively) at early stage of the disease. Cranial magnetic resonance imaging (MRI) showed mild supratentorial periventricular leukodystrophy, which was not specific. Sagittal cranial MRI demonstrated medulla oblongata and upper cervical cord atrophy called “tadpole atrophy”, which had high suggestive value. The results of gene analysis showed heterozygous mutation of glial fibrillary acidic protein gene, which had been reported as pathogenic gene; c.1091C>T (p.A364V) in exon 6, c.722C>T (p.R258C) in exon 4 and c.197G>A (p.R66Q) in exon 1, respectively.Conclusions:Type Ⅱ Alexander disease is an autosomal dominant disease, most with point mutations, rarely with deletion mutations. Type Ⅱ Alexander disease should be suspected when a patient had signs of lower brainstem involvement such as dizziness, ataxia, pyramidal sign, autonomic dysfunction, especially when cranial MRI showed mild supratentorial leukodystrophy, and medulla oblongata and upper cervical cord atrophy.

Vanadium dioxide-assisted broadband absorption and linear-to-circular polarization conversion based on a single metasurface design for the terahertz wave.

Integrating tunable characteristics and multiple functions into a single metasurface has become a new scientific and technological undertaking that needs to deal with huge challenges, especially in the terahertz frequency region. The multifunctional design combining the broadband absorption and broadband polarization conversion using a single switchable metasurface is proposed in this paper. The switchable performance can be realized by treating the insulation to metal phase transition properties of vanadium dioxide (VO2). At high temperature (74 °C), the proposed metasurface can be used as a broadband absorber which consists of a VO2 square ring, polyimide (PI) spacer, and VO2 film. Simulated results show that the terahertz wave absorption can reach above 90% with the bandwidth ratio of 75% in the frequency range of 0.74 THz-1.62 THz. This absorber is insensitive to polarization resulted from the symmetry structure and also shows a good performance at large incident angles. Once the temperature is lower than the cooling phase transition temperature (about 62 °C) and VO2 is in insulation state, the metasurface can be transformed into a broadband linear-to-circular polarization converter. Numerical simulation depicts that the ellipticity reaches to -1 and the axis ratio is lower than 3 dB from 1.47 THz to 2.27 THz. The designed switchable metasurface provides the potential to be used in the fields of advanced research and intelligent applications in the terahertz frequency region.

Enhanced charge transport via d(δ)-p(π) conjugation in Mo2-integrated single-molecule junctions.

A trans-dimolybdenum nicotinate (m-Mo2) complex and its isonicotinate isomer (p-Mo2) were synthesized and characterized crystallographically, and their single-molecule charge transport properties were investigated using the STM break junction (STM-BJ) technique. With a quadruply bonded Mo2 complex unit integrated into molecular backbones, the single-molecule conductance for complex molecules was increased by more than one order of magnitude compared with that of the organic π-conjugated analogues 1,4-bis(4-pyridyl)benzene (p-Ph) and 1,4-bis(3-pyridyl)benzene (m-Ph). More interestingly, unlike m-Ph, m-Mo2 with meta connected pyridyl anchors presents larger conductance than that of p-Mo2 with two para connected pyridyl groups. DFT-based transmission calculations revealed that the significant conductance enhancement of Mo2 molecules originates from the largely reduced HOMO-LUMO gap, and the unique d(δ)-p(π) conjugation between the Mo2 unit and the pyridine rings gives rise to a delocalized electronic structure that endows the Mo2 molecules with an unexpected high conductance.

Growth of High-Quality Superconducting FeSe0.5Te0.5 Films on Pb(Mg1/3Nb2/3)0.7Ti0.3O3 and Electric-Field Modulation of Superconductivity.

Heterostructures composed of superconductor and ferroelectrics (SC/FE) are very important for manipulating the superconducting property and applications. However, growth of high-quality superconducting iron chalcogenide films is challenging because of their volatility and FE substrate with rough surface and large lattice mismatch. Here, we report a two-step growth approach to get high-quality FeSe0.5Te0.5 (FST) films on FE Pb(Mg1/3Nb2/3)0.7Ti0.3O3 with large lattice mismatch, which show superconductivity at only around 10 nm. Through a systematic study of structural and electric transport properties of samples with different thicknesses, a mechanism to grow high-quality FST is discovered. Moreover, electric-field-induced remarkable change of Tc (superconducting transition temperature) is demonstrated in a 20 nm FST film. This work paves the way to grow high-quality films which contain volatile element and have large lattice mismatch with the substrate. It is also helpful for manipulating the superconducting property in SC/FE heterostructures.

Mediation of Electron Transfer by Quadrupolar Interactions: The Constitutional, Electronic, and Energetic Complementarities in Supramolecular Chemistry.

Studies of intermolecular interactions enhance our knowledge of chemistry across molecular and supramolecular levels. Here, we show that host-guest quadrupolar interaction has a profound influence on the molecular system. With covalently bonded dimolybdenum complex units as the electron donor (D) and acceptor (A) and a thienylene group (C4H2S) as the bridge (B), the mixed-valence D-B-A complexes are shaped with clefts in the middle of the molecule. Interestingly, in aromatic solvents, the D-A electronic coupling constants (Hab) and electron transfer rates (ket) are dramatically reduced. Theoretical computations indicate that an aromatic molecule is encapsulated in the cleft of the D-B-A array; quadrupole-quadrupole interaction between the guest molecule and the C4H2S bridge evokes a charge redistribution, which increases the HOMO-LUMO energy gap, intervening in the through-bond electron transfer. These results demonstrate that a supramolecular system is unified underlying the characteristics of the assembled molecules through constitutional, electronic, and energetic complementarities.

Gastric Seed: Towards Distributed Ultrasonically Interrogated Millimeter-Sized Implants for Large-Scale Gastric Electrical-Wave Recording.

This paper presents the concept of Gastric Seed, which is an ultrasonically interrogated millimeter-sized implant for gastric electrical-wave (also known as slow waves, SWs) recording. A network of Gastric Seeds can be endoscopically implanted within the stomach submucosal space for large-scale SW recording. This paper also summarizes our recent effort towards Gastric Seed development including ultrasonic self-regulated power management and addressable ultrasonic pulse-based data transfer. The proposed power management in the form of a voltage doubler only requires a single off-chip capacitor for simultaneous rectification, regulation and over-voltage protection (OVP) by utilizing ultrasonic transducer's internal capacitance and reverse current. For data transfer, sharp ultrasonic pulses are transmitted to reduce the implant's power consumption. A proof-of-concept addressable chip was fabricated in a 0.35-µm standard CMOS process. Utilizing two pairs of millimeter-sized stacked power/data ultrasonic transducers spaced by 3.75 cm in a water tank, the chip achieved measured regulated voltage of 3 V and data rate of 75 kbps with the data transmitter energy consumption of 440 pJ/bit.

A Multi-Beam Shared-Inductor Reconfigurable Voltage/SECE Mode Piezoelectric Energy Harvesting Interface Circuit.

This paper presents an autonomous multi-input (multi-beam) reconfigurable power-management chip for optimal energy harvesting from weak multi-axial human motion using a multi-beam piezoelectric energy harvester (PEH). The proposed chip adaptively operates in either voltage-mode or synchronous-electrical-charge-extraction-mode (VM-SECE) to improve overall efficiency, extract maximum energy regardless of the PEH beams' impedance/voltage/frequency variations, and protect the chip against large inputs, eliminating the need for high-voltage processes. It can simultaneously harvest energy from up to 6 beams using only one shared off-chip inductor. It uses an active negative voltage converter to extend the input-voltage range to as low as 35 mV. In addition, an active voltage doubler with a small footprint is implemented for faster cold start. A prototype VM-SECE chip was fabricated in a 0.35-µm 2P4M standard CMOS process occupying 1.9 mm2 active area. To fully characterize the chip performance, it was tested with both a commercial single-beam PEH and a custom-made PEH with five mechanically plucked thin-film beams. With the commercial PEH, compared to an on-chip full-wave active rectifier (FAR) with 95.6% efficiency, the VM-SECE chip harvested 3.28x more power for shock inputs at 1 Hz frequency and 4.39 g acceleration. With the custom 5-beam PEH for a pseudo-walking condition, compared to the on-chip FAR, the VM-SECE chip harvested 1.59x and 2.38x more power for 1-and 5-beam operations, respectively.