Single-double-band switchable optical circular polarizers based on surface plasmon resonance.

A single-double-band switchable circular polarization filter based on surface plasmon resonance exhibits significant potential for applications in fields such as communication and sensing due to its adjustable, low-cost, and easy integration features. In this study, we propose a bi-layer rod nanostructure and use FEM simulation to study the transmission spectra of the structure. The results demonstrate that the structure exhibits both single- and double-band circular polarization filtering effects, which can be switched by varying geometric parameters such as the distance between the two layers and the width of nanorods. Furthermore, the filtering effects of both single- and double-band are highly dependent on the length of the nanorods, with average extinction rates reaching 486 and 2020/129, respectively; the operating bandwidths (defined as extinction ratio >10) can reach 170 nm and 35 nm/70 nm, respectively. The underlying physical mechanisms are clarified by analyzing the electric dipole, magnetic dipole resonance modes, and induced chiral fields on nanostructures.

Single-double-band switchable optical circular polarizers based on surface plasmon resonance: publisher's note.

This publisher's note reports a correction in Appl. Opt.63, 1153 (2024)APOPAI0003-693510.1364/AO.513837.

Calreticulin, a potential coregulator of immune checkpoints and biomarker associated with tumor microenvironment and clinical prognostic significance in breast invasive carcinoma.

As a promising immune checkpoint of immunogenic cell death (ICD) and multifunctional calcium-binding molecular chaperone, calreticulin (CALR) has been attracting increasing attention. CALR mainly locates in cellular endoplasmic reticulum and significantly affects cell proliferation, invasion, induction of apoptosis, and angiogenesis in breast invasive carcinoma (BRCA). CALR overexpression might be correlated with a worse outcome. Nonetheless, it remains obscure how CALR correlates with immune infiltration and survival prognosis of BRCA. In this study, we investigated CALR expression utilizing RNAseq data from the cancer genome atlas (TCGA) and genotype-tissue expression (GTEx) database. The prognostic value of CALR was analyzed using clinical survival data. Enrichment analysis was conducted using the R package "clusterProfiler." We downloaded the immune cell infiltration score of TCGA samples from published articles and online databases and performed a correlation analysis between immune cell infiltration levels and CALR expression. We further assessed the association between CALR and immunomodulators. Moreover, we also evaluated the expression of CALR in 100 formalin-fixed and paraffin-embedded breast cancer and adjacent normal breast tissue specimens. Our results found that CALR was highly expressed in BRCA, and CALR expression levels differed in pathological stages, T stages, and N stages. Besides, these results suggested that CALR overexpression may have adverse effects on the progression-free interval (PFI) and disease-free interval (DFI), which may be related to tumor proliferation, invasion, and metastasis, leading to tumor deterioration. Meanwhile, immune cell infiltration analysis revealed a correlation between the expression of CALR and the number of neutrophils and dendritic cells, suggesting that CALR was highly correlated with many immunomodulators in BRCA. Our results provide potential biomarkers of CALR in BRCA. CALR may interact synergistically with other immunomodulators to regulate the immune microenvironment, which could be utilized to develop new immunotherapy drugs.

Varicella-zoster virus early infection but not complete replication is required for the induction of chronic hypersensitivity in rat models of postherpetic neuralgia.

Herpes zoster, the result of varicella-zoster virus (VZV) reactivation, is frequently complicated by difficult-to-treat chronic pain states termed postherpetic neuralgia (PHN). While there are no animal models of VZV-induced pain following viral reactivation, subcutaneous VZV inoculation of the rat causes long-term nocifensive behaviors indicative of mechanical and thermal hypersensitivity. Previous studies using UV-inactivated VZV in the rat model suggest viral gene expression is required for the development of pain behaviors. However, it remains unclear if complete infection processes are needed for VZV to induce hypersensitivity in this host. To further assess how gene expression and replication contribute, we developed and characterized three replication-conditional VZV using a protein degron system to achieve drug-dependent stability of essential viral proteins. Each virus was then assessed for induction of hypersensitivity in rats under replication permissive and nonpermissive conditions. VZV with a degron fused to ORF9p, a late structural protein that is required for virion assembly, induced nocifensive behaviors under both replication permissive and nonpermissive conditions, indicating that complete VZV replication is dispensable for the induction of hypersensitivity. This conclusion was confirmed by showing that a genetic deletion recombinant VZV lacking DNA packaging protein ORF54p still induced prolonged hypersensitivities in the rat. In contrast, VZV with a degron fused to the essential IE4 or IE63 proteins, which are involved in early gene regulation of expression, induced nocifensive behaviors only under replication permissive conditions, indicating importance of early gene expression events for induction of hypersensitivity. These data establish that while early viral gene expression is required for the development of nocifensive behaviors in the rat, complete replication is dispensable. We postulate this model reflects events leading to clinical PHN, in which a population of ganglionic neurons become abortively infected with VZV during reactivation and survive, but host signaling becomes altered in order to transmit ongoing pain.

Communication between mothers with breast cancer and minor children: a qualitative systematic review and meta-synthesis.

PURPOSE: Both women with breast cancer and their minor children were affected by a breast cancer diagnosis. The purpose of this review was to synthesize the evidence from qualitative studies on illness-related communication between mothers with breast cancer and their minor children from mothers' perspectives. METHODS: A thorough systematic review and meta-synthesis of qualitative studies was conducted. English articles published prior to 6 November 2021 were searched from five databases, including PubMed/ MEDLINE, EMBASE, Web of Science, CINAHL, and PsycINFO. After screening the titles, abstracts, and full texts, seven articles were finally included in the quality appraisal and meta-aggregation. RESULTS: Four synthesized findings were derived from seven articles, including disclosure dilemma, factors impacting disclosure, methods of communication, and information needs. CONCLUSIONS: This systematic review offered insight into the communication between mothers with breast cancer and their minor children. Various factors influenced the decision-making process on illness-related disclosure, as well as the methods and contents of the communication. Future studies should be undertaken to explore the common model shared by mothers and children who have had comparable experiences, as well as to completely analyze the differences between different cultures in this topic.

Observation on the aerosol and ozone precursors in suburban areas of Shenzhen and analysis of potential source based on MAX-DOAS.

Long-term stereoscopic observations of aerosol, NO2, and HCHO were carried out at the Yangmeikeng (YMK) site in Shenzhen. Aerosol optical depths and NO2 vertical column concentration (NO2 VCD) derived from MAX-DOAS were found to be consistent with other datasets. The total NO2 VCD values of the site remained low, varying from 2 × 1015 to 8 × 1015 mol/cm2, while the HCHO VCD was higher than NO2 VCD, varying from 7 × 1015 to 11 × 1015 mol/cm2. HCHO VCD was higher from September to early November than that was from mid-late November to December and during February 2021, in contrast, NO2 VCD did not change much during the same period. In January, NO2 VCD and HCHO VCD were both fluctuating drastically. High temperature and HCHO level in the YMK site is not only driving the ozone production up but also may be driving up the ozone concentration as well, and the O3 production regime in the YMK site tends to be NOx-limited. At various altitudes, backward trajectory clustering analysis and Potential Source Contribution Function (PSCF) were utilized to identify possible NO2 and HCHO source locations. The results suggested that the Huizhou-Shanwei border and the Daya Bay Sea area were the key potential source locations in the lower (200 m) and middle (500 m) atmosphere (WPSCF > 0.6). The WPSCF value was high at the 1000 m altitude which was closer to the YMK site than the near ground, indicating that the pollution transport capability in the upper atmosphere was limited.

Modified Northern blot protocol for easy detection of mRNAs in total RNA using radiolabeled probes.

BACKGROUND: Northern blotting is still used as a gold standard for validation of the data obtained from high-throughput whole transcriptome-based methods. However, its disadvantages of lower sensitivity, labor-intensive operation, and higher quality of RNA required limit its utilization in a routine molecular biology laboratory to monitor gene expression at RNA level. Therefore, it is necessary to optimize the traditional Northern protocol to make the technique more applicable for standard use. RESULTS: In this paper, we report modifications and tips used to improve the traditional Northern protocol for the detection of mRNAs in total RNA. To maximize the retention of specifically bound radiolabeled probes on the blot, posthybridization washes were performed under only with moderate-stringency until the level of radioactivity retained on the filter decreased to 20~50 counts per second, rather than normally under high and low stringency sequentially for scheduled time or under only high stringent condition. Successful detection of the low-expression gene using heterologous DNA probes in 20 µg of total RNA after a two-day exposure suggested an improvement in detection sensitivity. Quantitatively controlled posthybridization washes combined with an ethidium bromide-prestaining RNA procedure to directly visualize prestained RNA bands at any time during electrophoresis or immediately after electrophoresis, which made the progress of the Northern procedure to be monitored and evaluated step by step, thereby making the experiment reliable and controllable. We also report tips used in the modified Northern protocol, including the moderate concentration of formaldehyde in the gel, the accessory capillary setup, and the staining jar placed into an enamel square tray with a lid used for hybridization. Using our modified Northern protocol, eight rounds of rehybridization could be performed on a single blot. The modification made and tips used ensured the efficient proceeding of the experiment and the resulting good performance, but without using special reagents or equipment. CONCLUSIONS: The modified Northern protocol improved detection sensitivity and made the experiment easy, less expensive, reliable, and controllable, and can be employed in a routine molecular biology laboratory to detect low-expressed mRNAs with heterologous DNA probes in total RNA.

Knockdown of IGF2BP3 inhibits the tumorigenesis of gallbladder cancer and modifies tumor microenvironment.

Gallbladder cancer (GBC) ranks seventh among the gastrointestinal cancers. Messenger RNAs (mRNAs) could regulate the progression of GBC. For the purpose of exploring the targets for GBC treatment, RNA sequencing was used to identify the differential expressed mRNAs between GBC and adjacent tissues. Next, CCK8 assay was used to assess the cell viability, and cell proliferation was investigated by colony formation assay. Flow cytometry was performed to evaluate the cell apoptosis. Protein and mRNA expression were analyzed by western blot and RT-qPCR, respectively. Transwell was performed to evaluate the cell metastasis. GBC-derived exosomes were isolated with ultracentrifugation. To evaluate the function of exosomes in GBC, in vivo model of GBC was constructed. The data revealed IGF2BP3 was identified to be upregulated in GBC, and IGF2BP3 silencing was able to decrease GBC cell proliferation by promoting the apoptosis. The migration and invasion of GBC cells were reduced by IGF2BP3 knockdown. Silencing of IGF2BP3 obviously suppressed the level of p-STAT3 in GBC cells. Meanwhile, GBC cell-derived exosomes notably promoted macrophage M2 polarization via carrying IGF2BP3, and then the polarized macrophages promoted the malignant behavior of GBC cells. Furthermore, exosomes markedly promoted the tumor growth of GBC via promoting macrophage M2 polarization. In summary, knockdown of IGF2BP3 suppressed the malignant behavior of GBC cells. Additionally, knockdown of IGF2BP3 modified tumor microenvironment during the progression of GBC. Thus, these findings might provide a new theoretical basis for exploring a strategies against GBC.

Breast-Conserving Surgery is Oncologically Safe for Well-Selected, Centrally Located Breast Cancer.

OBJECTIVE: The aim of this study was to evaluate the long-term survival outcomes of breast-conserving surgery (BCS) in centrally located breast cancer (CLBC) compared with mastectomy in CLBC and BCS in non-CLBC, based on the Surveillance, Epidemiology, and End Results (SEER) database. METHODS: Female patients aged < 80 years with unilateral T1-T2 invasive ductal or lobular breast cancer undergoing BCS or mastectomy were enrolled. The differences in clinical-pathological characteristics were evaluated using Chi square tests. Multivariate logistic regression was used to measure the relationship between predictive variables and performing BCS in CLBC. Survival outcomes were estimated using the Kaplan-Meier method and compared using Cox proportional hazards models. To overcome the effects of baseline differences on survival outcome in patients treated with BCS in the central and upper-outer locations, a 1:1 ratio propensity score matching method was performed. RESULTS: Overall, among 16,522 CLBC patients, 7982 cases (48.3%) underwent BCS between 1998 and 2015. Factors such as older age, Black race, invasive ductal carcinoma (IDC), grade I, small tumor size, none or limited lymph node metastasis, positive progesterone receptor status, and receiving chemotherapy were independently correlated with BCS. BCS was an independent favorable prognostic factor among CLBC patients, based on multivariate Cox analysis. It was also shown that CLBC had similar survival outcomes compared with tumors in the upper-outer quadrant, and had a better breast cancer-specific survival compared with tumors in the lower quadrants, based on multivariate Cox analysis. CONCLUSIONS: BCS should be an acceptable and preferable alternative to mastectomy for well-selected, early-stage T1 or T2 CLBC.

Localization of a Gaussian beam in an electrically tunable curved Airy channel in a paraelectric Mn:KLTN crystal.

An optical Airy channel is built in a paraelectric Mn: KLTN crystal via a photo-induced Airy beam based on the photo-refractive effect. A laser beam, incident with the main lobe of the Airy channel, propagates along the Airy channel with a bias field as the control parameter. We find that the light beam is nicely confined in the Airy channel and propagates along it, presenting Airy-like properties of non-diffraction and bending action under a certain voltage range; then a breathing soliton can be formed with bias electric field rising, originating from space-charge-field-induced nonlocal refractive index perturbation. The experiment is corroborated by simulation. This Letter opens up new possibilities for fabricating an electrical engineering functional device, such as optical routing.

Post-mastectomy immediate breast reconstruction is oncologically safe in well-selected T4 locally advanced breast cancer: a large population-based study and matched case-control analysis.

PURPOSE: Although it is well accepted that the survival outcome is most probably unaffected by immediate breast reconstruction (IBR) for T1-T3 tumors, the safety of IBR in T4 locally advanced breast cancer (LABC) remains unclear. METHODS: By using data from the Surveillance, Epidemiology, and End Results (SEER) database, the trend of IBR for female T4 LABC patients undergoing mastectomy, chemotherapy and radiotherapy was explored. The predictors of IBR in T4 LABC were evaluated by multivariate logistic regression. The survival outcomes were compared by means of Cox hazards models adjusting for known clinicopathological variables and stratifying on the T stage and contralateral prophylactic mastectomy (CPM). RESULTS: Altogether 714 cases underwent IBR between 1998 and 2015. The IBR cohort had a lower percentage of cases with T4d disease whereas higher percentage with CPM. The IBR rate was 10.1% and increased from 4.1% in 1998 to 17.7% in 2015. Since 2009, the rate of implant-based IBR exceeded that of the autologous tissue method. An age less than 45 years (OR 2.930, 95% CI 2.299-3.735) and CPM (OR 2.758, 95% CI 2.306-3.299) were the strongest predictors of IBR. In the 1:2 matched case-control analysis, IBR was not an independent prognostic factor for breast cancer specific-survival (BCSS) (HR 0.893, p = 0.236, 95% CI 0.741-1.077) and overall survival (OS) (HR 0.886, p = 0.183, 95% CI 0.741-1.059). BCSS and OS were similar among patients undergoing IBR whether they underwent CPM or not and whether they were inflammatory breast cancer (IBC) or not. CONCLUSIONS: IBR is oncologically safe in well-selected T4 LABC.

The Prognostic Significance of the Oncotype DX Recurrence Score in T1-2N1M0 Estrogen Receptor-Positive HER2-Negative Breast Cancer Based on the Prognostic Stage in the Updated AJCC 8th Edition.

BACKGROUND: This study aimed to evaluate the prognostic significance of the Oncotype DX recurrence score (RS) in T1-2N1M0 estrogen receptor (ER)-positive, human epidermal growth factor receptor 2 (HER2)-negative breast cancer based on the prognostic stage in the updated American Joint Commission on Cancer, 8th edition. METHODS: The Surveillance, Epidemiology, and End Results database was searched to identify ER-positive invasive ductal breast cancer in T1-2N1M0 with RS results diagnosed between 2004 and 2012. Patients with RS were categorized into low-risk (RS < 11), intermediate-risk (RS 11-25), and high-risk (RS > 25) groups. The distributions of clinical-pathological characteristics were compared among the RS risk groups using Pearson's Chi square. Breast cancer-specific survival (BCSS) and overall survival (OS) were estimated using the Kaplan-Meier method and compared across RS groups using the log-rank statistic. Cox models were fitted to assess the factors independently associated with survival. RESULTS: The study enrolled 4059 cases categorized into prognostic stages IA to IIB. The RS risk groups were positively correlated with pathological prognostic stages (P < 0.001). The RS risk groups differed significantly in terms of BCSS and OS (P < 0.001). According to the multivariate analysis, RS risk group was an independent prognostic factor for BCSS and OS together with the pathological prognostic stage. The subgroup analysis showed similar survival rates across pathological prognostic stages in the RS low-risk group but significant differences in survival rates among pathological prognostic stages in the RS intermediate-risk group. The survival rates among the RS risk groups also differed significantly in pathological prognostic stage IA. CONCLUSIONS: Oncotype DX RS provided independent prognostic significance to complement the prognostic staging system.

Growing Trends of Contralateral Prophylactic Mastectomy and Reconstruction in Young Breast Cancer.

BACKGROUND: The aim of this study was to evaluate the trends of surgical treatments among young patients in T1N0-1M0 stage based on the Surveillance, Epidemiology, and End Results database. MATERIALS AND METHODS: Patients aged less than 40 y diagnosed between 1998 and 2015 were enrolled, with tumors in T1N0-1M0 stage and not located in the central area. Differences in clinical-pathological characteristics were evaluated using chi-square tests. Multivariate logistic regression was used to measure the various factors associated with contralateral prophylactic mastectomy (CPM). Independent prognostic factors were evaluated by Cox model. RESULTS: The total rate of breast-conserving surgery (BCS) was 51.6%, which declined from 64.5% in 1998 to 39.6% in 2015. The total rate of CPM was 22.7%, which increased from 3.7% in 1998 to 38.7% in 2014 despite a decline to 32.7% in 2015. Meanwhile, the rate of reconstruction increased in line with that of CPM, from 9.4% in 1998 to 35.0% in 2015. There was a trend of increasing use of implant-based reconstruction. Significant higher odds of CPM were found in recent year of diagnosis between 2010 and 2015 and in implant-based reconstruction. Patients undergoing CPM had similar survival outcomes compared with those undergoing BCS and unilateral mastectomy, whereas those undergoing BCS had better survival outcomes compared with those undergoing unilateral mastectomy. CONCLUSIONS: A trend of growing preference for CPM and reconstruction was observed among young patients in early stage in recent years without survival benefits. Efforts should be made to promote efficient communication and evidence-based decision-making.

Broadband circular polarizer based on twisted plasmonic nano-disks.

The broadband circular polarizer based on the surface plasmon of a metal nanostructure has important practical application due to its adjustability, low cost, and easy integration. In this article, a twisted multilayer double semi-disc structure is designed to allow for a broadband circular polarizer, whose transmission spectra are simulated using the finite element method under left-handed circularly polarized and right-handed circularly polarized extinction. The results show a large extinction ratio up to 900 for properly designed geometry and a broad bandwidth (defined as extinction ratio >10) of 50-160 nm. Additionally, the broadband position, bandwidth, and extinction rate are all sensitive to some geometric parameters, such as rotation angle, disk radius, and more, and the mechanism of this phenomenon is clarified by exploring the plasmon electromagnetic resonance on nanostructures.

Tunable broadband circular polarizer based on ultrahigh-order surface plasmonic resonance.

Circular polarizers have potential applications in optical communication and liquid crystal display. In this paper, a multilayer twisted nanoring-rod nanostructure is designed. The finite element method is used to explore the surface plasmon of the structure under the excitation of left-handed circularly polarized light and right-handed circularly polarized light. The results show that the structure can be used as a polarizer in the tunable operating bandwidth of 400-1290 nm, and tunability is achieved by changing the filling medium near the structure instead of the geometric parameters of the nanostructures. We qualitatively reveal the physical mechanism of this phenomenon from the perspective of plasmon resonance coupling by plotting the charge distribution at several specific wavelengths.

Multiband circular dichroism from bilayer rotational F4 nanostructure arrays.

A chiral nanostructure array is designed, which is composed of a bilayer rotational F4-shaped nanoarray configuration. The surface plasmon resonance and circular dichroism are studied by changing the parameters of the structure. The results show that the structure has strong multiband circular dichroism, which is attributed to the coupling of the layers. In theory, based on the Born-Kuhn model, the upper and lower nanostructures are equivalent to electric dipoles. By analyzing the coupling mode of electric dipoles in the upper and lower layer, the mechanism of circular dichroism and the shift of the circular dichroism resonance are revealed. Besides, there are several specific modes that are fault tolerant of fabrication issues. This feature unveils the bright prospect of spectral anti-interference. So, the suggested chiral nanostructure can be used in biologically targeted molecular detection and spectral sensing.

Low dose Emodin induces tumor senescence for boosting breast cancer chemotherapy via silencing NRARP.

PURPOSE: The resistance to 5-FU often limits its clinical effectiveness on breast cancer treatment. Combination therapy thus is employed to overcome this treatment resistance. We here report a potent antitumor effect of Emodin at low dose on chemotherapy sensitivity of MCF-7 breast cancer cells. METHODS: Cell viability, apoptosis, glutathiones (GSH) concentration and Reactive oxygen species (ROS) activity following Emodin and 5-FU treatment was assessed. Cellular senescence following combined treatment and silence of NRARP was examined by senescence-associated ß-galactosidase analysis. Western blot analysis was used to determine changes in the expression of p21, p16, p27, E2F1 and NRARP. RESULTS: Low dose Emodin potentiates 5-FU-induced apoptosis of breast cancer cells, in association with inhibition of NRARP, resulting in cellular senescence. RNA interference of NRARP induced cellular senescence in MCF-7 breast cancer cells. Furthermore, the cellular senescence induced by Emodin and 5-FU treatment could be reverted by pcDNA-NRARP. CONCLUSION: These findings provide preclinical evidence for repurposing use of Emodin in combination with chemotherapeutic agents to treat breast cancer as an alternative salvage regimen.

Arctigenin induced gallbladder cancer senescence through modulating epidermal growth factor receptor pathway.

Gallbladder cancer has poor prognosis and limited therapeutic options. Arctigenin, a representative dibenzylbutyrolactone lignan, occurs in a variety of plants. However, the molecular mechanisms involved in the antitumor effect of arctigenin on gallbladder cancer have not been fully elucidated. The expression levels of epidermal growth factor receptor were examined in 100 matched pairs of gallbladder cancer tissues. A positive correlation between high epidermal growth factor receptor expression levels and poor prognosis was observed in gallbladder cancer tissues. Pharmacological inhibition or inhibition via RNA interference of epidermal growth factor receptor induced cellular senescence in gallbladder cancer cells. The antitumor effect of arctigenin on gallbladder cancer cells was primarily achieved by inducing cellular senescence. In gallbladder cancer cells treated with arctigenin, the expression level of epidermal growth factor receptor significantly decreased. The analysis of the activity of the kinases downstream of epidermal growth factor receptor revealed that the RAF-MEK-ERK signaling pathway was significantly inhibited. Furthermore, the cellular senescence induced by arctigenin could be reverted by pcDNA-epidermal growth factor receptor. Arctigenin also potently inhibited the growth of tumor xenografts, which was accompanied by the downregulation of epidermal growth factor receptor and induction of senescence. This study demonstrates arctigenin could induce cellular senescence in gallbladder cancer through the modulation of epidermal growth factor receptor pathway. These data identify epidermal growth factor receptor as a key regulator in arctigenin-induced gallbladder cancer senescence.

Polarization dependence of plasmon enhanced fluorescence on Au nanorod array.

The spatial anisotropy of Au nanorod results in two distinct orientational modes by which the polarization orientation dependence of excitation and emission can be studied. In this work, a periodical distributed metallic nanostructure substrate, which contains an array of Au nanorods, is synthesized, and the polarization dependence of the plasmon enhanced fluorescence effect is investigated experimentally and numerically. It is found that the fluorescence emission enhancement of organic probe fluorophores located at the surface of Au nanorods depends on the polarization angle very sensitively. Different polarization orientations of the excitation light result in very different enhancement effects. As a result, the change of the polarization orientation of the excitation light can be a sensitive marker of surface chemistry and other possible practical applications.

Analysis of α-helix unfolding in the pine nut peptide Lys-Cys-His-Lys-Pro induced by pulsed electric field.

BACKGROUND: A variety of analytical techniques were applied to explore the effects of pulsed electric field (PEF) on α-helix structural changes in the novel antioxidant peptide Lys-Cys-His-Lys-Pro (KCHKP, 611.76 Da). RESULTS: The relative α-helix content of the KCHKP peptide was significantly altered from 100% to 89.91 ± 0.97% when the electric pulse frequency was 1800 Hz and the field intensity was 10 kV cm-1 . Moreover, the 1,1-diphenyl-2-pycryl-hydrazyl (DPPH) and 2,2-azinobis diammonium salt (ABTS) radical-scavenging activities of PEF-treated KCHKP were increased from 56.31% ± 0.74% to 84.33% ± 1.23% and from 40.56% ± 0.78% to 51.33% ± 0.27%, respectively. CONCLUSION: PEF treatment increased peptide linkage stretch vibration and altered hydrogen bonding of KCHKP. The stability of the α-helix structure was influenced by hydrogen bonds within the peptide linkage of KCHKP induced by PEF and was related to changes in antioxidant activity. © 2017 Society of Chemical Industry.