COVID-19 and bone health.

A few patients who have recovered from COVID-19 develop persistent or new symptoms that last for weeks or months; this is called "long COVID" or "post-COVID-19 syndrome." Over time, awareness of the short- and long-term consequences of COVID-19 has increased. The pulmonary consequences are now fairly well established, but little is known about the extrapulmonary system of COVID-19, particularly its effects on bones. Current evidence and reports indicate a direct relationship between SARS-CoV-2 infection and bone health, with SARS-CoV-2 having a significant negative effect on bone health. In this review, we analyzed the impact of SARS-CoV-2 infection on bone health and assessed the impact of COVID-19 on the diagnosis and treatment of osteoporosis.

[The expression and clinical significance of neutrophil myeloperoxidase in patients with myeloperoxidase-antineutrophil cytoplasmic antibody associated vasculitis].

Objective: To investigate the expression and clinical significance of neutrophil myeloperoxidase (MPO) in patients with MPO-antibody associated vasculitis (AAV). Methods: Thirty-six newly diagnosed MPO-AAV patients who were hospitalized in the First Affiliated Hospital, Anhui Medical University from July 2018 to June 2021 were enrolled,and 36 age and sex matched healthy subjects were selected as controls. Neutrophil MPO level was detected by flow cytometry (FCM) and MPO mRNA was tested by real time quantitative polymerase chain reaction (RT-qPCR) in all subjects. Serum complement fragment C5 (C5a) and MPO in both groups and serum MPO-anti-antineutrophilic cytoplasmic antibody(ANCA) in MPO-AAV group were measured by enzyme linked immunosorbent assay (ELISA), while the disease activity was evaluated by Birmingham vasculitis activity score-V3 (BVAS-V3). Results: Compared with the heathy control group, the expression of MPO mRNA in neutrophils, serum MPO and complement C5a in MPO-AAV group were significantly higher[MPO mRNA:30.2±11.5 vs. 1.9±0.6, P<0.001;MPO:(112.0±68.7) IU/L vs. (87.4±22.9) IU/L, P=0.01; C5a:(187.3±90.3) ng/ml vs. (107.3±31.1) ng/ml, P<0.001; respectively], while the mean fluorescence intensity (MFI) of MPO in neutrophils were significantly lower [ 1 343.3±723.4 vs. 2 868.0±1 136.5, P<0.001]. In MPO-AAV group, the expression of neutrophil MPO mRNA was positively correlated with serum MPO-ANCA and MPO levels (r=0.537, P=0.001 and r=0.358, P=0.032; respectively). Multiple regression analysis suggested that neutrophil MPO mRNA expression was positively correlated with serum MPO-ANCA level (ß=0.695, P=0.006); neutrophil MPO level was negatively correlated with serum MPO-ANCA, MPO and complement C5a levels (r=-0.335, P=0.046; r=-0.372, P=0.026; r=-0.577, P<0.001; respectively). Further, neutrophil MPO level was negatively correlated with serum complement C5a level (ß=-0.374, P=0.043). BVAS-V3 was positively correlated with MPO mRNA expression in neutrophils, serum MPO-ANCA, MPO and complement C5a (r=0.598, P<0.001; r=0.599, P<0.001; r=0.537, P=0.001; r=0.415, P=0.012; respectively) and negatively correlated with MPO level in neutrophils (r=-0.342, P=0.041). In multiple regression analysis it suggested that BVAS-V3 was positively correlated with MPO mRNA expression in neutrophils (ß=0.511, P=0.002). Conclusion: In MPO-AAV patients, MPO synthesis and release in neutrophils are both significantly increased, which might be influenced by serum MPO-ANCA and C5a, respectively. Furthermore, MPO synthesis activity in neutrophils is an independent factor related to disease activity.

[Protein expressions of matrix metalloproteinase-9 and its inhibitor and their ratio changes in wound healing of patients with stages â ¢ and â £ pressure ulcers].

Objective: To explore the expression levels of matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of metalloproteinase-1 (TIMP-1) protein and the change of MMP-9/TIMP-1 ratio in wound exudates of patients with stages Ⅲ and Ⅳ pressure ulcers during wound healing. Methods: From July 2017 to July 2018, 30 patients with stage Ⅲ pressure ulcers [30 wounds, 16 males and 14 females, aged (65±10) years] and 34 patients with stage Ⅳ pressure ulcers [50 wounds, 17 males and 17 females, aged (65±9) years] admitted to Hebei General Hospital who met the inclusion criteria were enrolled in this prospective cohort study. According to the principle of wound treatment and the characteristics and needs of wound in different periods, individualized intervention measures were formulated for patients and appropriate dressings were selected. At the time of admission and on 7, 14, 21, 28 days of treatment, the healing of pressure ulcer wounds was evaluated by Pressure Ulcer Healing Scale. Afterwards, the wound exudate was collected at each time point to detect the expression levels of MMP-9 and TIMP-1 protein by enzyme-linked immunosorbent assay, and the MMP-9/TIMP-1 ratio was calculated. Data were processed with analysis of variance for repeated measurements of single group and linear trend test. Results: (1) There were significantly statistical differences in wound healing scores of patients with stages Ⅲ and Ⅳ pressure ulcers among the time of admission and on 7, 14, 21, 28 days of treatment within each stage (F=145.382, 153.234, P<0.01), and they all showed a gradually decreasing trend (F=170.466, 284.585, P<0.01). (2) At the time of admission and on 7, 14, 21, 28 days of treatment, the expression levels of MMP-9 protein in wound exudates of patients with stages Ⅲ and Ⅳ pressure ulcers were (171±104), (138±88), (110±70), (85±55), (62±41) ng/L and (193±107), (173±104), (139±83), (114±70), (89±56) ng/L, respectively. There were significantly statistical differences within each stage (F=58.007, 111.680, P<0.01), and they all showed a gradually decreasing trend (F=62.901, 134.628, P<0.01). At the time of admission and on 7, 14, 21, 28 days of treatment, the expression levels of TIMP-1 protein in wound exudates of patients with stages Ⅲ and Ⅳ pressure ulcers were (6.2±3.9), (5.6±3.4), (5.1±3.1), (4.4±2.5), (3.8±2.3) ng/L and (4.8±2.5), (4.7±2.6), (4.4±2.6), (4.6±2.7), (4.1±2.4) ng/L, respectively. There were significantly statistical differences within each stage (F=25.479, 7.778, P<0.01), and there was a gradually decreasing trend in stage Ⅲ (F=62.901, P<0.01) and a decreasing trend in stage Ⅳ (F=134.628, P<0.01). At the time of admission, the expression levels of MMP-9 and TIMP-1 in wound exudates of patients with stage Ⅲ pressure ulcers were similar to those of patients with stage Ⅳ pressure ulcers (t=-1.03, 1.47, P>0.05). (3) At the time of admission and on 7, 14, 21, 28 days of treatment, the MMP-9/TIMP-1 ratios in the wound exudates of patients with pressure ulcers of stages Ⅲ and Ⅳ were 30±13, 25±9, 22±9, 20±8, 17±6 and 43±19, 37±13, 32±10, 26±9, 22±9, respectively. There were significantly statistical differences within each stage (F=37.173, 97.191, P<0.01), and they all showed a gradually decreasing trend (F=54.183, 130.088, P<0.01). At the time of admission, the MMP-9/TIMP-1 ratio in wound exudates of patients with stage Ⅳ pressure ulcers was significantly higher than that of patients with stage Ⅲ pressure ulcers (t=-3.42, P<0.01). Conclusions: During the wound healing process of patients with stages Ⅲ and Ⅳ pressure ulcers, the expression levels of MMP-9 and TIMP-1 protein and the MMP-9/TIMP-1 ratio in wound exudates show a decreasing trend. The stage of wound healing can be predicted according to the expression level of MMP-9 protein and the MMP-9/TIMP-1 ratio.

[Advances in the research of influence of pH value on healing of chronic wounds].

Chronic wounds are with characteristics of long last time and cannot heal in time, which is a problem in clinic. Wound pH value plays an important role in the process of healing of chronic wounds. In this paper, we review the relative researches on wound pH value and wound microenvironment, summarize the potential relationship between wound pH value and healing of chronic wounds, as well as the method to change pH value of chronic wounds, thereby to provide theoretical basis for the treatment of chronic wounds in clinic.

[SMARCA4-deficient primary thoracic sarcoma:a clinicopathological analysis of five cases].

Objective: To investigate the clinicopathological characteristics of SMARCA4- deficient thoracic sarcomas. Methods: The clinical features and CT scans of SMARCA4-deficient thoracic sarcomas (n=5) diagnosed at Fudan University Cancer Hospital from December 2016 to October 2018 were reviewed. Hematoxylin-eosin staining, immunohistochemistry and targeted next generation sequencing were performed in available cases along with a literature review. Results: All 5 patients were males with age ranging from 32 to 65 years (average 54 years; median 61 years). Four patients were smokers except one with unknown smoking history. The average maximum diameter of tumor was 5.6 cm. Tumor primary sites included thoracic wall,thoracic cavity,lung and mediastinum. Histologically,tumor cells formed solid sheets or anastomosing islands with brisk mitotic figures accompanying with large areas of necrosis. Three cases focally exhibited rhabdoid morphology and vesicular chromatin. Immunohistochemically, SMARCA4, SMARCA2 and Claudin-4 were negative in all cases and all tumors demonstrated SOX2 and SMARCB1 nuclear positive staining. Among 3 cases analyzed by targeted next generation sequencing, concurrent SMARCA4 and p53 mutation was detected in all three cases. Mutations of STK11, ERBB4, NF2, GNAS, MTOR,MET and FGFR1 amplification were also detected among the three cases. The follow-up information was available in all 5 cases. Two patients died of the tumor. One relapsed multiple times after surgeries but was alive with disease. Two patients received radical excisions without relapse. Conclusions: SMARCA4-deficient thoracic sarcoma is a rare but highly-aggressive tumor with dismal prognosis. The tumor is featured by rhabdoid morphology histologically and distinctive immunohistochemical and molecular phenotype.

[The clinical significance of circulating follicular helper T cells in patients with anti-neutrophil cytoplasmic myeloperoxidase antibody-associated vasculitis].

Objective: To investigate the change of circulating follicular helper T cells (cTfh) in patients with anti-neutrophil cytoplasmic myeloperoxidase antibody-associated vasculitis (MPO-AAV), and to analyze the relationship between cTfh and disease activity. Methods: Thirty-eight untreated MPO-AAV patients (patient group) and thirty-eight healthy volunteers (control group) were enrolled in this study. cTfh and membrane expression of inducible co-stimulator (ICOS) and programmed cell death protein 1 (PD-1) were detected by flow cytometry (FCM). Serum anti-neutrophil cytoplasmic myeloperoxidase antibody (MPO-ANCA) was measured by ELISA. Disease activity was evaluated by Birmingham vasculitis activity score (BVAS). Results: Compared with those in control group, the proportions of cTfh, ICOS(+)Tfh and PD-1(+) Tfh cells in patient group were significantly higher [(25.9±3.8)% vs. (21.0±5.3)%, P<0.001; (1.8±0.8)% vs. (0.8±0.5)%, P<0.001 and (10.2±2.8)% vs. (8.2±2.2)%, P=0.001, respectively]. Meanwhile, the expression of ICOS and PD-1 on cTfh in patient group was markedly more intensive (59.6±10.0 vs.49.2±6.9, P<0.001 and 532.6±104.2 vs. 485.1±73.4, P=0.025, respectively). In patient group, the proportion of cTfh was positively correlated with the ratio of ICOS(+)Tfh, the expression of ICOS, the level of MPO-ANCA and BVAS (r=0.407, P=0.011; r=0.705, P<0.001; r=0.737, P<0.001 and r=0.663, P<0.001, respectively). The expression intensity of ICOS on cTfh was positively associated with ICOS(+)Tfh ratio, serum MPO-ANCA and BVAS (r=0.388, P=0.016; r=0.645, P<0.001 and r=0.653, P<0.001, respectively). Nevertheless, the expression of PD-1 on cTfh was only positively correlated with the ratio of PD-1(+) Tfh (r=0.473, P=0.003). Conclusions: Enhanced cTfh in patients with MPO-AAV might produce MPO-ANCA, which is related to the aggravation of MPO-AAV. Thus, cTfh and its ICOS could be potentially targeted for the treatment of MPO-AAV.

[Reconsidering on the drug therapy of adult laryngopharyngeal reflux disease].

The treatment for laryngopharyngeal reflux diseases consist of general treatment, medical therapy and surgical treatment, among which, drug therapy is still the main effective way. Proton pump inhibitor is adopted as the first drug for patients with laryngopharyngeal reflux disease only caused by acid reflux. With standardized treatment, the majority of symptoms in laryngopharyngeal reflux disease could be alleviated effectively. PPI therapy, while seeming logical, is less useful in patients with reflux hypersensitivity, weak acid or non acid reflux, neuropsychic factors and gastroesophageal reflux disease. This article aims to investigate bewilderment and challenge faced by clinicians when managing adult laryngology reflux disease with medical therapy.

[The significances of peripheral neutrophils CD(55) and myeloperoxidase expression in patients with myeloperoxidase-specific anti-neutrophil cytoplasmic antibody associated vasculitis].

Objective: To investigate the expression of CD(55) and myeloperoxidase (MPO) on neutrophils in patients with MPO-specific anti-neutrophil cytoplasmic antibody associated vasculitis(MPO-AAV), and analyze the relationship between the expression and clinical manifestation. Methods: Forty untreated patients with active MPO-AAV (patient group) and 30 healthy volunteers (control group) were enrolled in this study. The CD(55) on neutrophils and both membrane and cytoplasmic MPO were detected by flow cytometry. Serum fragment-from the activated complement factor B(Ba) and MPO were measured by ELISA. The clinical activity of vasculitis was valued by Birmingham vasculitis activity score-version 3(BVAS-V3). The significance of laboratory data was evaluated by Spearman correlation test and multivariate linear regression analysis. Results: (1)The mean fluorescence intensity(MFI) of CD(55) expressed on neutrophils was significantly higher than that in control group[4 068.6±2 306.0 vs 2 999.5±1 504.9, P=0.033]. Similar results of serum MPO and Ba in patient group were found compared to controls [500.0(381.0, 612.7) IU/L vs 286.9(225.5, 329.1) IU/L, P<0.001; 35.2(25.2, 79.5) ng/L vs 18.0(15.0, 28.0) ng/L, P<0.001], respectively. However, MIF of cytoplasmic MPO in patients was significantly lower than that of control group(1 577.1±1 175.9 vs 3 105.3±2 323.0, P=0.003) . (2) In patient group, cytoplasmic intensity of MPO was negatively associated with the serum levels of MPO(r=-0.710, P<0.001) and Ba (r=-0.589, P=0.001). Moreover, serum MPO was positively associated with serum Ba(r=0.691, P<0.001). Membrane intensity of CD(55) on neutrophils was positively correlated with patient age (r=0.514, P=0.001), C reactive protein (r=0.376, P=0.018), peripheral neutrophils count (r=0.485, P=0.001) and BVAS-V3 (r=0.484, P=0.002), whereas negative correlation between membrane CD(55) and disease duration was seen (r=-0.403, P=0.01). (3) The result of multiple linear regression analysis showed there was statistically significant positive correlation between MFI of CD(55) expressed on neutrophils and BVAS-V3 (ß=0.001, P=0.027). Conclusions: In MPO-AAV, CD(55) expression on neutrophils is markedly enhanced, which is one of the independent risk factors related to disease activity. It might protect neutrophils from attacking AAV, CD(55) expression on neutrophils is markedly enhanced, which is one of the independent risk factors related to disease activity. It might protect neutrophils from attacking by complement alternative pathway. Activated neutrophils release more MPO and lysosome to intensify the inflammation reaction and aggravate the disease. Thus CD(55) might become a new potential target for the treatment of this disease in the future.

[Comparative analysis of hepatitis B virus large protein, hepatitis B virus-DNA and Pre-S1 antigen in evaluating serum hepatitis B virus replication].

Objective: To investigate the comparative study of serum hepatitis B virus (HBV) large protein (HBV-LP) , HBV-DNA, and Pre S1 antigen (Pre S1-Ag) detection in the evaluation of serum HBV replication in patients with chronic hepatitis B. Methods: A total of 482 patients infected with chronic hepatitis B virus (CHB) were enrolled and the serums were collected in a hospital of Hefei city in Anhui province from June 2013 to March 2015. The serum HBV-LP, HBV markers(HBV-M) and Pre S1-Ag were detected using ELISA, and HBV-DNA were quantified using quantitative real-time PCR. The positive detection rate difference of HBV-DNA, HBV-LP and Pre S1-Ag were compared, the correlation between the logarithm of HBV-DNA copies number and the absorbance value of HBV-LP was analyzed using Spearman rank correlation. Results: The positive rates of HBV DNA, HBV-LP, and Pre S1-Ag were 67.22% (324/482), 73.86% (356/482), and 37.34% (180/482), respectively (P<0.01). The positive rates of the three markers were 54.57% (185/339), 64.90% (220/339), and 27.73% (94/339), respectively, in 339 HBeAg-negative CHB patients (P<0.01). In HBeAg negative patients, the positive rate of HBV-LP in 185 cases of HBV-DNA positive samples was 90.81% (168/185), which was higher than that of Pre S1-Ag with rate of 39.46% (73/185) (P<0.01).The positive rate of HBV-LP was 33.77% (52/154) in 154 cases of patients with negative HBV-DNA whose positive rate was higher than Pre S1-Ag with positive rate of 13.64% (21/154)(P<0.01). The positive rates of HBV-DNA, HBV-LP and Pre S1-Ag in HBsAg, HBeAg and HBcAb positive groups were 97.04% (131/135), 94.81% (128/135), and 60.00% (81/135), (P<0.01); The positive rates of three indexes of HBsAg, HBeAb, HBcAb positive group were 53.74% (122/227), 63.88% (145/227), and 27.31% (62/227); The positive rates of three indexes of HBsAg and HBcAb positive group were 55.79% (53/95), 67.37% (64/95), and 28.42% (27/95) (P<0.01). The absorbance value of HBV-LP was positively related with the logarithm of HBV-DNA copies number (Spearman rank correlation coefficient was 0.908, P<0.01). Conclusion: There was a good correlation between HBV-LP and HBV-DNA load value, and could be used as an effective complement for the detection of HBV-DNA and HBV-M. Compared with Pre S1-Ag.

[Hodgkin's lymphoma of salivary gland: a case report].

Hodgkins lymphoma (HL) of salivary gland is extremely rare. We reported a bilateral HL in a female of 58 years old, whose main clinical complaint was bilateral enlargement of parotid gland and cervical lymph nodes. The clinical symptoms were relieved after intermittent treatment by anti-inflammatory drugs and traditional Chinese herbs resulted in misdiagnosis of chronic lymphadnitis. The postoperative pathological diagnosis was HL of parotid gland, submandibular gland and cervical lymph nodes. It implies that lymphoma shall also be take into consideration even if anti-inflammatory drugs and Chinese traditional herbs have treatment effect on a parotid gland mass.

Posttraumatic administration of a sub-anesthetic dose of ketamine exerts neuroprotection via attenuating inflammation and autophagy.

As a complex disease, traumatic brain injury (TBI) can result in long-term psychiatric changes and sensorimotor and cognitive impairments. The TBI-induced loss of memory and long-term cognitive dysfunction are related to mechanistic factors including an increased inflammatory response, autophagy, edema, and ischemia. Many published studies have offered evidence for the neuroprotective effects and anti-inflammatory properties of ketamine for TBI patients. Nonetheless, there is a limited understanding of the accurate mechanism that underlies the potential neuroprotective effects of ketamine. Herein, it can be shown that posttraumatic administration of ketamine at a sub-anesthetic dose (10mg/kg ketamine, every 24h up to 7days) can prevent the TBI-induced production of IL-6 and TNF-α, attenuate deficits of dendrites and spines and exert beneficial effects on memory and behavior. Moreover, studies show that ketamine may activate the mTOR signaling pathway by p-mTOR induction to down-regulate the expression of crucial autophagic proteins such as LC3 and Beclin-1. According to these findings, ameliorating secondary brain injury and anti-inflammatory properties is closely related to the neuroprotection of ketamine, which supports the use of ketamine as a potential therapy for patients with TBI to alleviate functional deficits.

Ammonia intercalated flower-like MoS2 nanosheet film as electrocatalyst for high efficient and stable hydrogen evolution.

Ammonia intercalated flower-like MoS2 electrocatalyst film assembled by vertical orientated ultrathin nanosheet on graphite sheethas been successfully synthesized using one-step hydrothermal method. In this strategy, ammonia can effectively insert into the parallel plane of the MoS2 nanosheets, leading to the expansion of lattice and phase transfer from 2H to 1T, generating more active unsaturated sulfur atoms. The flower-like ammoniated MoS2 electrocatalysts with more active sites and large surface area exhibited excellent HER activity with a small Tafel slope and low onset overpotential, resulting a great enhancement in hydrogen evolution. The high efficient activity and recyclable utilization, as well as large-scale, indicate that it is a very promising electrocatalyst to replace Pt in industry application.

Analysis of the relationship between peripheral blood T lymphocyte subsets and HCV RNA levels in patients with chronic hepatitis C.

We investigated the relationship between peripheral blood T lymphocyte subsets and hepatitis C virus (HCV) RNA levels in patients with hepatitis C. Samples from 69 chronic hepatitis C (CHC) patients and 20 healthy controls were analyzed using quantitative polymerase chain reaction (PCR) to detect HCV RNA and flow cytometry to determine the expression levels of CD3, CD4, and CD8 in lymphocytes. The percentage of CD4+ T cells (42.87 ± 6.11%) and the ratio of CD4+/CD8+ (1.34 ± 0.25) in these patients were significantly lower than those in the healthy control group (49.55 ± 6.68%, 1.82 ± 0.11, respectively) (P < 0.01, P < 0.01), while the percentage of CD8+ T cells (32.78 ± 5.48%) was higher than that in the control group (27.35 ± 4.32%) (P < 0.01). There was no significant difference in the percentage of CD3+ T cells between the two groups (P > 0.05). With the increase in HCV RNA replication, the percentage of CD8+ T cells increased gradually, while the CD4+ T cell percentage and CD4/CD8 ratio decreased. The change in the percentage of T lymphocyte subsets may be one of the reasons for persistent HCV infection, and the high expression levels of HCV RNA might be the reason for the low frequency of CD4+ T lymphocytes in patients with chronic HCV.

Tunable hybridization in metal nanoshell chains.

We have studied the coupled surface plasmon (SP) modes in periodic metal nanoshell chains by including long range electromagnetic interactions. The eigen-decomposition method is used to analyze the dispersion and dissipation of the SP modes. The resulting band structure can be understood as a hybridization between a hole band and a particle band with a structurally tunable band gap in the middle of the first Brillouin zone. The mode quality, which is defined as the imaginary part of the generalized polarizability, increases as the shell thickness decreases. This indicates a larger energy loss and an increasing coupling between the bands. Through the manipulation of the band structures, the propagation of the coupled SP modes in the nanoshell chain can be controlled.

The fabrication and characteristics of indium-oxide covered porous InP.

Uniform and vertical indium-oxide nanotube (IONT) arrays embedded well in n-type InP single crystal have been successfully prepared in situ by porous InP-template-assisted chemical vapor deposition (CVD). This IONT/InP nanostructure reveals high sensitivity to humidity at room temperature, which is ascribed to the ultrahigh surface-to-volume ratio of this nanostructure and the large number of oxygen defected states in IONTs. Such a nanostructure of IONT arrays embedded in a III-V semiconductor substrate could be expected to have potential applications, such as superior gas sensors. This work provides a novel approach for fabricating low-melting metal oxide semiconductor nanotubes.

Integration of single-crystalline nanocolumns into highly ordered nanopore arrays.

The arrangement of nanostructures into desired well-ordered architectures is crucial for the realization of functional nanodevices and has been the focus of current nanotechnology. Existing physical and chemical approaches have the ability to assemble nanostructures, but it is still a challenge to arrange basic nanostructures into a highly ordered designed pattern. Here, we report a novel method to integrate tin-doped indium oxide single-crystalline nanocolumns into highly ordered two-dimensional nanopore patterns through radio-frequency magnetron sputtering by the aid of porous alumina membranes (PAMs). We have further demonstrated that the morphology of the assembled nanopore arrays is controllable by adjusting either the PAM configurations or sputtering conditions. Our present method provides the possibility of a general approach for nanounit integration, and these assembled regular nanopore arrays pave the way for the application of novel filters and sensors.

Formation of uniform and square nanopore arrays on (100) InP surfaces by a two-step etching method.

Uniform and square single-crystal InP nanopore arrays have been successfully fabricated on a (100) n-InP surface by a two-step etching method. The characteristic of slow etching rates in four equivalent crystalline (011) facets of (100) n-InP in a mixture of pure HCl and pure H(3)PO(4) has been found, which is the main reason for the formation of square single-crystal InP nanopores. The distribution of nanopores can be closely associated with the distribution of carriers in the semiconductor during the electrochemical etching process. An oscillating behaviour of current has been observed, which can probably be attributed to the oscillations in concentration of the electrolyte at the pore tips caused by diffusion of the electrolyte in the nanopore channels.