Proteomic data show an increase in autoantibodies and alpha-fetoprotein and a decrease in apolipoprotein A-II with time in sera from senescence-accelerated mice

We evaluated changes in levels by comparing serum proteins in senescence-accelerated mouse-prone 8 (SAMP8) mice at 2, 6, 12, and 15 months of age (SAMP8-2 m, -6 m, -12 m, -15 m) to age-matched SAM-resistant 1 (SAMR1) mice. Mice were sacrificed, and blood was analyzed by 2-dimensional electrophoresis combined with mass spectrometry. Five protein spots were present in all SAMP8 serum samples, but only appeared in SAMR1 samples at 15 months of age except for spot 3, which also showed a slight expression in SAMR1-12 m sera. Two proteins decreased in the sera from SAMP8-2 m, -6 m, and -12 m mice, and divided into 2 spots each in SAMP8-15 m sera. Thus, the total number of altered spots in SAMP8 sera was 7; of these, 4 were identified as Ig kappa chain V region (M-T413), chain A of an activity suppressing Fab fragment to cytochrome P450 aromatase (32C2_A), alpha-fetoprotein, and apolipoprotein A-II. M-T413 is a monoclonal CD4 antibody, which inhibits T cell proliferation. We found that M-T413 RNA level was significantly enhanced in splenocytes from SAMP8-2 m mice. This agreed with serum M-T413 protein alterations and a strikingly lower blood CD4⁺ T cell count in SAMP8 mice when compared to the age-matched SAMR1 mice, with the latter negatively correlating with serum M-T413 protein volume. Age-related changes in serum proteins favored an increase in autoantibodies and alpha-fetoprotein and a decrease of apolipoprotein A-II, which occurred in SAMP8 mice at 2 months of age and onwards. These proteins may serve as candidate biomarkers for early aging.

Reliability, validity and sensitivity of the Chinese (simple) short form 36 health survey version 2 (SF-36v2) in patients with chronic hepatitis B

The purpose of the study was to evaluate reliability, validity and sensitivity of the Chinese (simple) SF-36v2 in patients with chronic hepatitis B (CHB). Four hundred and sixty patients were recruited and allocated to CHB (CHB without cirrhosis) (n = 323) and CHB-related cirrhosis (n = 137) groups. Internal consistency reliability was estimated with Cronbach's α-coefficient. Convergent and discriminant validity were assessed by item-scale-component correlation. Factorial validity was explored by principal component factor analysis with varimax rotation. Sensitivity was measured with Cohen's effect size (ES), and independent sample t-test between the CHB and CHB-related cirrhosis groups and between alanine aminotransferase (ALT) normal and abnormal groups after stratifying illness stages. The results showed that Cronbach's α of the total SF-36v2 was 0.92, with the range from 0.72 to 0.87 in the eight scales and 0.76 to 0.77 in the two summary components. Most of the hypothesized item-scale-component correlations were 0.40 or over, and all of such hypothesized correlations were higher than the alternative ones, indicating satisfactory convergent and discriminant validity. Two and seven factors were extracted after varimax rotation at the scale level and item level. The eligible ES with statistically significant independent sample t-test was found in the physical component summary (PCS) and physical function (PF), role-physical (RP), general health (GH), vitality (VT), social functioning (SF) scales by comparison between CHB and CHB-related cirrhosis groups, and in the PCS and PF, GH, SF scales by comparison between the ALT normal and abnormal groups in the stratification of patients with CHB. In conclusion, the Chinese (simple) SF-36v2 has acceptable reliability, validity and sensitivity in patients with CHB.

Reversal of optical binding force by Fano resonance in plasmonic nanorod heterodimer

We present calculations of the optical force on heterodimer of two gold nanorods aligned head-to-tail, under plane wave illumination that is polarized along the dimer axis. It is found that near the dipole-quadrupole Fano resonance, the optical binding force between the nanorods reverses, indicating an attractive to repulsive transition. This is in contrast to homodimer which in similar configuration shows no negative binding force. Moreover, the force spectrum features asymmetric line shape and shifts accordingly when the Fano resonance is tuned by varying the nanorods length or their gap. We show that the force reversal is associated with the strong phase variation between the hybridized dipole and quadrupole modes near the Fano dip. The numerical results may be demonstrated by a near-field optical tweezer and shall be useful for studying "optical matters" in plasmonics.

Effect of mild hypothermia on breast cancer cells adhesion and migration

To explore the effect of mild hypothermia (35ºC) on breast cancer cells adhesion to vascular endothelial cells, a parallel plant flow chamber was used to observe the adhesion of human breast cancer cells MDA-MB-231 to endothelial cells Eahy926 under physiological flow at 35ºC and 37ºC, as well as the role of intercellular adhesion molecule 1 (ICAM-1) in this process. Further, the effect of mild hypothermia (35ºC) on migration of MDA-MB-231 was also studied. Our results show that mild hypothermia can inhibit the adhesion of tumor cells to endothelial cells and ICAM-1 plays an important role in this process. However, mild hypothermia inhibits breast cancer cell adhesion in a way independent on the change of ICAM-1 expression under our experimental conditions. Mild hypothermia can weaken the chemotaxis of breast cancer cells while it has no obvious effect on unidirectonal migration capacity. These results suggest that mild hypothermia could be used as a potentially adjunct treatment combined with surgery to decrease tumor cell adhesion and migration.

MR imaging of human pancreatic cancer xenograft labeled with superparamagnetic iron oxide in nude mice

The aim of this work was to investigate the MRI findings on tumor xenografts induced in nude mice by the inoculation of human pancreatic cancer cells labeled with superparamagnetic iron oxide (SPIO), and to monitor the kinetics of SPIO distribution in tumor xenografts. The labeled cancer cells were subcutaneously inoculated into 11 nude mice to induce tumor xenograft. The unlabeled cancer cells served as a control inoculated into nine nude mice. MR imaging was performed with a 1.5 T MR scanner for the tumor xenograft at the first, second and third week after the inoculation. We found that the tumor xenograft was induced in 100% nude mice on MR imaging for both groups in the first week after the inoculation. In the SPIO group, the tumors showed homogeneous hypointensity on T₁ - and T₂ -weighted and FIESTA images 1 week after inoculation. Two and 3 weeks after inoculation, the center of the tumors was still hypointense on all the above sequences. The tumor periphery was isointense on T₁ -weighted, and hyperintense on T₂ -weighted and FIESTA images. The tumors in control group were homogeneously hypointense or isointense on T₁ -weighted, and hyperintense on T₂ -weighted and FIESTA images in the first, second and third week after the inoculation. The size and signal-to-noise ratio of the tumor center in the SPIO group had decreased subsequent to the inoculation in all T₁ - and T₂ -weighted images and FIESTA. Our results showed the human pancreatic cancer cells labeled with SPIO can induce tumor xenograft in nude mice and MRI can monitor the kinetics of SPIO distribution in tumor xenografts.

Renal and perirenal space involvement in acute pancreatitis: An MRI study

OBJECTIVES

To study the prevalence and characteristics of renal and perirenal space involvement and its relation to the severity of acute pancreatitis (AP) using MRI.

METHODS

115 patients with AP who underwent MRI with the clinical kidney function test were retrospectively analyzed in this study. MRI sequences included conventional and diffusion weighted imaging (DWI) sequences. The renal and perirenal space involvement in AP was noted on MRI. The renal apparent diffusion coefficient (ADC) on DWI was measured for each kidney. The severity of AP on MRI was graded using MR severity index (MRSI). The relationships among the renal and perirenal space involvement on MRI, the renal ADC, MRSI and the results of the kidney function test were analyzed.

RESULTS

In the 115 patients with AP, the renal and perirenal space abnormalities detected included renal parenchymal abnormalities (0.8%), abnormalities of the renal collecting system (2.6%), renal vascular abnormalities (1.7%), thickened renal fascia (99%), perirenal stranding (62%) and perirenal fluid collection (40%). The prevalence of perirenal space abnormalities was correlated with the severity of AP based on MRSI (P<0.05). The renal ADC values were lower in patients with abnormal kidney function than in those without kidney injury (P<0.05). The prevalence of kidney function abnormalities was 9.4%, 32% and 100% in mild, moderate, and severe AP cases, respectively (P=0.00).

CONCLUSION

Perirenal space involvement is much more than renal parenchymal involvement in AP. The prevalence of perirenal space involvement in AP on MRI has a positive correlation with the severity of AP according to MRSI.

MR imaging of acute pancreatitis: correlation of abdominal wall edema with severity scores

OBJECTIVE

To study MRI findings of abdominal wall edema (AWE) in acute pancreatitis as well as correlations between AWE and the severity of acute pancreatitis according to the MR severity index (MRSI) and the Acute Physiology And Chronic Healthy Evaluation III (APACHE III) scoring system.

MATERIALS AND METHODS

A total of 160 patients with AP admitted to our institution between December 2009 and March 2011 were included in this study. MRI was performed within 48 h after admission. MRI findings of acute pancreatitis were noted, including AWE on the MRI. The abdominal wall area was divided into quarters, and each area involved was recorded as 1 point to score the severity of AWE. The severity of acute pancreatitis was studied using both the MRSI and the APACHE III scoring system. Spearman correlation of AWE with the MRSI and the APACHE III scoring system was analyzed.

RESULTS

In 160 patients with acute pancreatitis, 53.8% had AWE on MRI. The average AWE score was 1.2±1.4 points. The prevalence of AWE was 30.5%, 64.5% and 100% in mild, moderate and severe AP, respectively, according to MRSI. AWE on MRI was correlated with MRSI scores (r=0.441, p=0.000). According to APACHE III scores, the averages were 2.0±1.1 and 2.6±1.1 points in mild AP and severe AP, respectively (P=0.016). AWE was slightly correlated with the APACHE III scores (r=0.222, p=0.005).

CONCLUSION

AWE on MRI in acute pancreatitis is common, which may be a supplementary indicator in determining the severity of AP.

Inhibiting the color formation by gradient temperature-elevating Maillard reaction of soybean peptide-xylose system based on interaction of l-cysteine and Amadori compounds

Light color and savory flavor enhancer are attractive for consumers and food producers. The effect of addition time of l-cysteine on inhibiting color formation was investigated in soybean peptide-xylose system, and the possible pathway was explored. Once dicarbonyl compounds were formed during the Maillard reaction, the addition of l-cysteine had no color-inhibiting effect; if l-cysteine was added immediately after the Amadori compound was formed, the extraordinary color-inhibiting effect was observed. Therefore, an improved way to inhibit color formation was proposed on the basis of the interaction of l-cysteine and Amadori compounds by controlling the addition time of l-cysteine through gradient temperature-elevating Maillard reaction. The system was heated at 80 °C for 60 min to form Amadori compounds, followed by the addition of L-cysteine, and the temperature was raised to 120 °C and held for 110 min. Compared with traditional products, the lightest color product was found desirable by GC/MS analysis and sensory evaluation. The novel method proposed can be a guide for the industrial preparation of light-colored products.

Gallbladder patterns in acute pancreatitis: an MRI study

RATIONALE AND OBJECTIVES

The aim of this study was to assess the gallbladder patterns on magnetic resonance imaging (MRI) associated with acute pancreatitis (AP).

MATERIALS AND METHODS

There were 197 patients with AP, all of whom had undergone abdominal MRI. AP was categorized as either edematous or necrotizing according to its findings on MRI and graded as mild (0-3 points), moderate (4-6 points), or severe (7-10 points) according to the magnetic resonance severity index. The changes to the walls and dimensions of the gallbladder and common bile duct, in addition to the presence of biliary stones and pericholecystic fluid, were noted and compared with the severity of AP on the basis of the magnetic resonance severity index.

RESULTS

Of the 197 patients with AP, 81% were classified as edematous and 19% as necrotizing on MRI. There were 35%, 59%, and 6% of patients with mild, moderate, and severe AP according to the magnetic resonance severity index, respectively. Seventy-six percent of patients had at least one gallbladder abnormality on MRI, including a thickened gallbladder wall (42%), pericholecystic fluid (38%), gallbladder stones (35%), an enlarged gallbladder (24%), dilatation of the common bile duct (16%), and subserosal edema (15%). Eighty-nine percent of patients (34 of 38) with necrotizing AP had gallbladder abnormalities, which was significantly higher than the 72% of patients (115 of 159) with edematous AP (P < .05). The prevalence of gallbladder abnormalities was 64% in patients with mild AP, 81% in those with moderate AP, and 91% in those with severe AP (P < .05 among the three groups).

CONCLUSIONS

Most patients with AP have gallbladder abnormalities on MRI, including a thickened gallbladder wall and pericholecystic fluid. The prevalence of gallbladder abnormalities has a positive correlation with the severity of AP on MRI.

High-frequency ultrasonic transducer based on lead-free BSZT piezoceramics

This paper describes the fabrication and evaluation of a high-frequency (40MHz) transducer based on lead-free piezoceramics for ultrasonic imaging. The transducer with an aperture size of 0.9mm has been fabricated using barium strontium zirconate titanate ((Ba(0.95)Sr(0.05))(Zr(0.05)Ti(0.95))O(3), abbreviated as BSZT) ceramics. The lead-free BSZT has a piezoelectric d(33) coefficient of 300 pC/N and an electromechanical coupling factor k(t) of 0.45. High-frequency ultrasound transducers were fabricated and a bandwidth of 76.4% has been achieved with an insertion loss of -26dB. Applications in high resolution biological and medical imaging could be possible with this lead-free material.

Cryopreservation of adult bovine testicular tissue for spermatogonia enrichment

To develop a procedure for cryopreservation of adult bovine testis tissue, the effects of dimethyl sulphoxide (DMSO), propylene glycol (PG), ethylene glycol (EG), and their concentrations (v/v), as well as different thawing temperatures, on the cell viability of bovine testis tissue after freezing/thawing were examined. The highest testicular cell viabilities came from the media containing DMSO (85.3 ± 1.2 percent), PG (82 ± 1.0 percent) and EG (83.4 ± 1.0 percent) at 10 percent concentration respectively. Using 10 percent DMSO gave significantly higher spermatogonia percentage (61.1 ± 1.2 percent, P < 0.001) than processing with 10 percent PG (54.3 ± 0.6 percent) or 10 percent EG (55 ± 1.8 percent) after differential plating. Thawing in water bath of 37 or 97-100 degree C also provided significantly higher viabilities (85.1 ± 1.0, 85 ± 1.0 percent, P < 0.01, respectively) and spermatogonia percentages (56.6 ± 2.0, 56.6 ± 2.6 percent, P < 0.01, respectively) than that thawing at 4C (23.4 ± 0.8 percent for total viability, 8.97 ± 1.0 percent for spermatogonia percentage). Collectively, 10 percent DMSO and thawing in 37-100 degree C water baths were appropriate for the cryopreservation of bovine testicular tissue and subsequent spermatogonia enrichment.

Plasma ferritin levels, genetic variations in HFE gene, and coronary heart disease in Chinese: a case-control study

BACKGROUND

The association between body iron stores and coronary heart disease (CHD) was inconsistent. We sought to explore this association in Chinese Han population and further examine the association of the variations in hemochromatosis (HFE) gene and CHD risk.

METHODS

We conducted a case-control study including 1334 CHD patients and 1334 age- and sex-frequency matched controls. The plasma ferritin levels were measured by enzyme linked immunosorbent assay. Genotypes of the tagging single nucleotide polymorphisms (tagSNPs) were determined by TaqMan SNP allelic discrimination.

RESULTS

The plasma ferritin levels in CHD cases (197.9μg/L [2.7-932.9μg/L]) were higher than those in controls (179.9μg/L [21.1-878.2μg/L]; P=0.028). The odds ratios (ORs) across the tertiles of plasma ferritin levels were 1.0 (reference), 0.93 (0.76-1.13), and 1.23 (1.02-1.48; P for trend=0.028). Adjustment for the traditional risk factors attenuated the associations to null (P for trend=0.22). Compared with the TT genotype of tagSNP rs9366637, subjects with C allele had higher risk of CHD (OR=1.35 for TC and 1.76 for CC; P=0.001 and <0.001 respectively). After adjustment for the conventional risk factors the results remained unchanged. We did not find significantly different plasma ferritin levels among different genotypes of rs9366637 (P=0.52).

CONCLUSIONS

The plasma ferritin levels were not significantly associated with CHD risk. However, the SNP rs9366637 in HFE gene was associated with higher CHD risk in Chinese Han population. The underlie mechanism remained to be elucidated in further studies.

Genetic diversity of mitochondrial cytochrome b gene in Chinese native buffalo

The origins of the domestic water buffalo remain contentious. To better understand the origins of Chinese water buffalo, we sequenced the complete mitochondrial cytochrome b (MT-CYB) gene from 270 individuals representing 13 Chinese domestic swamp buffalo populations. We found genetic evidence of introgression of river buffalo into Chinese swamp buffalo herds. Swamp buffalo haplotypes can be divided into two highly divergent lineages (A and B), suggesting that Chinese native swamp buffalo have two maternal origins. We found that the A→G transition in the buffalo MT-CYB gene stop codon resulted in buffalo haplotypes being terminated by one of two stop codons: AGA or AGG. AGA is common to river buffalo and lineage A of swamp buffalo, while AGG is specific to lineage B of swamp buffalo. Lineage A appears to have been domesticated in China. Further genetic evidence is required to clarify the origins of lineage B.

An integrated microfluidic chip with 40 MHz lead-free transducer for fluid analysis

The design, fabrication, and evaluation of a high-frequency transducer made from lead-free piezoceramic for the application of microfluidic analysis is described. Barium strontium zirconate titanate [(Ba(0.95)Sr(0.05))(Zr(0.05)Ti(0.95))O(3), abbreviated as BSZT] ceramic has been chosen to be the active element of the transducer. The center frequency and bandwidth of this high-frequency ultrasound transducer have been measured to be 43 MHz and 56.1%, respectively. The transducer was integrated into a microfluidic channel and used to measure the sound velocity and attenuation of the liquid flowing in the channel. Results suggest that lead-free high-frequency transducers could be used for in situ analysis of property of the fluid flowing through the microfluidic system.

Tunable visual color filter using microfluidic grating

This paper reports a tunable visual color filter based on a microfluidic transmission grating. The grating lines are formed by the microflows in an array of evenly spaced straight microchannels. In experimental study, the transmission of white light measures a shift of visual color from red to blue in the zeroth order diffraction in response to a change of the refractive index from 1.3290 to 1.3782 in the microflows. The merit of large tunability of transmission peak (Δλ=408 nm) makes this grating potential for various applications in biological and chemical measurements, such as space- and time-resolving micropattern spectrophotometers and separation of the fluorescence from the excitation.

Optofluidic refractometer using resonant optical tunneling effect

This paper presents the design and analysis of a liquid refractive index sensor that utilizes a unique physical mechanism of resonant optical tunneling effect (ROTE). The sensor consists of two hemicylindrical prisms, two air gaps, and a microfluidic channel. All parts can be microfabricated using an optical resin NOA81. Theoretical study shows that this ROTE sensor has extremely sharp transmission peak and achieves a sensitivity of 760 nm∕refractive index unit (RIU) and a detectivity of 85 000 RIU(-1). Although the sensitivity is smaller than that of a typical surface plasmon resonance (SPR) sensor (3200 nm∕RIU) and is comparable to a 95% reflectivity Fabry-Pérot (FP) etalon (440 nm∕RIU), the detectivity is 17 000 times larger than that of the SPR sensor and 85 times larger than that of the FP etalon. Such ROTE sensor could potentially achieve an ultrahigh sensitivity of 10(-9) RIU, two orders higher than the best results of current methods.

Optofluidic planar reactors for photocatalytic water treatment using solar energy

Optofluidics may hold the key to greater success of photocatalytic water treatment. This is evidenced by our findings in this paper that the planar microfluidic reactor can overcome the limitations of mass transfer and photon transfer in the previous photocatalytic reactors and improve the photoreaction efficiency by more than 100 times. The microreactor has a planar chamber (5 cm×1.8 cm×100 μm) enclosed by two TiO(2)-coated glass slides as the top cover and bottom substrate and a microstructured UV-cured NOA81 layer as the sealant and flow input∕output. In experiment, the microreactor achieves 30% degradation of 3 ml 3×10(-5)M methylene blue within 5 min and shows a reaction rate constant two orders higher than the bulk reactor. Under optimized conditions, a reaction rate of 8% s(-1) is achieved under solar irradiation. The average apparent quantum efficiency is found to be only 0.25%, but the effective apparent quantum efficiency reaches as high as 25%. Optofluidic reactors inherit the merits of microfluidics, such as large surface∕volume ratio, easy flow control, and rapid fabrication and offer a promising prospect for large-volume photocatalytic water treatment.

Optofluidic microcavities: Dye-lasers and biosensors

Optofluidic microcavities are integrated elements of microfluidics that can be explored for a large variety of applications. In this review, we first introduce the physics basis of optical microcavities and microflow control. Then, we describe four types of optofluidic dye lasers developed so far based on both simple and advanced device fabrication technologies. To illustrate the application potential of such devices, we present two types of laser intracavity measurements for chemical solution and single cell analyses. In addition, the possibility of single molecule detection is discussed. All these recent achievements demonstrated the great importance of the topics in biology and several other disciplines.

The CSN1S1 N and F alleles identified by PCR-SSCP and their associations with milk yield and composition in Chinese dairy goats

A method was depicted to identify null allele CSN1S1 N and low allele CSN1S1 F of the CSN1S1 gene of goat using PCR-SSCP (polymerase chain reaction-single strand conformation polymorphism). First, primer A was designed to amplify the exon 9 of CSN1S1 gene which produced three genotypes AA, AB, and BB. Among these three genotypes, only AA and AB individuals had a cytosine deletion at exon 9 after DNA sequencing, which cannot be used to identify the N and F alleles. Therefore, primer B was used to amplify intron 14 of CSN1S1 of described AA and AB individuals. Genotypes FF, FN and NN were detected within AA individuals and genotypes FO and NO were detected in the above AB individuals. The frequencies of F and N alleles in 708 samples from Xinong Saanen (XS) and Guanzhong (GZ) dairy goat breeds were 0.1139, 0.0927, and 0.2376, 0.1193, respectively. In 268 XS samples, the individuals with NN genotype contained a significant lower protein content than that of other genotypes (P<0.01). Individuals of FF genotype had significant higher milk yield than that of NO genotype in the first milk lactation of 202 XS individuals (P<0.05). Therefore, the variability at CSN1S1 locus contains enough genetic diversity to be potentially useful in improving the quality and production of milk in Chinese dairy goat breeds.

Correlation between tumor perfusion and lipiodol deposition in hepatocellular carcinoma after transarterial chemoembolization

PURPOSE

To study the correlation of tumor perfusion with lipiodol deposition in hepatocellular carcinoma (HCC) after transarterial chemoembolization with multidetector computed tomography (MDCT) perfusion imaging.

MATERIALS AND METHODS

MDCT perfusion imaging was performed in 24 patients with HCC 1 to 7 days before chemoembolization. The computed tomography (CT) perfusion parameters, such as hepatic arterial perfusion (HAP), hepatic portal perfusion (HPP), total liver perfusion (TLP), and hepatic arterial perfusion index (HAPI), were calculated with the slope method. The follow-up CT scans (noncontrast) were performed 4 weeks after chemoembolization to analyze lipiodol deposition. The lipiodol deposition in the tumor was classified into three grades and compared with CT perfusion parameters before chemoembolization.

RESULTS

The HAP and TLP of tumors before chemoembolization were correlated with the grades of lipiodol deposition in tumors after chemoembolization (r = 0.768, P < .0001 and r = 0.616, P = .001, respectively). However, the HPP and HAPI of the tumors were not related to the grades of iodized oil deposition (r = 0.227, P = .286 and r = 0.111, P = .607, respectively). Higher HAP was correlated with better lipiodol deposition, and lower HAP was correlated with poorer lipiodol deposition.

CONCLUSIONS

MDCT perfusion imaging has the potential to help select more appropriate patients with HCC for chemoembolization.

Pure angular momentum generator using a ring resonator

This paper reports a pure angular momentum generator using a ring resonator surrounded by a group of nano-rods. The evanescent waves of the circulating light in the ring are scattered by the nano-rods and generate a rotating electromagnetic field, which has only angular momentum but no linear momentum along the axis of rotation. The angular order is determined by the difference between the order of Whispering Gallery mode and the number of the rods, the rotating frequency is equal to the light frequency divided by the angular order. The maximum amplitude of the rotating electromagnetic fields can be 10 times higher than the amplitude of the input field when there are 36 rods (R(rod) = 120 nm, nr = 1.6). The pure angular momentum generator provides a new platform for trapping and rotation of small particles.

Low energy-consumption plasma electrolytic oxidation based on grid cathode

Plasma electrolytic oxidation (PEO) has attracted widespread attention owing to the simplicity of operation and the excellent properties of the formed coating. However, wider applications of PEO have been limited due to the high power consumption. This work describes the design and performance of a novel technique named shorter distance PEO (SD-PEO), which is intended for lowering the energy consumption. The key feature of the method is the application of grid cathode to eliminate the gaseous envelope effect and to block of the exchange of charge carries during SD-PEO process. Compared to PEO carried out at a normal electrode distance, e.g., 50 mm, both the voltage drop and the joule heat consumed in the electrolyte at a shorter distance, e.g., of 5 mm (SD-PEO) are relatively small. Consequently, the energy consumption rendered by the novel SD-PEO method may decrease by more than 25%. Our results reveal that SD-PEO is a low energy-consumption microarc oxidation technique with more potential in industry applications.