[Progress on the pathogenesis of chronic thromboembolic pulmonary hypertension]

Chronic thrombotic pulmonary hypertension (CTEPH) is a rare progressive pulmonary vascular disease, which is classified as World Health Organization (WHO) functional class Ⅳ pulmonary arterial hypertension (PAH). The diagnosis was based on mean pulmonary arterial pressure ≥25 mmHg(1 mmHg=0.133 kPa) and pulmonary arterial wedge pressure ≤15 mmHg measured by right heart catheterization, with the under-utilization of radionuclide ventilation/perfusion scan and regular anticoagulation therapy for at least three months. The incidence of CTEPH is low, at 4 cases per million population per year. Despite the in-depth research on CTEPH in recent years, the strengthening of clinical diagnostic awareness, and the emergence of treatment methods such as pulmonary endarterectomy (PEA) and balloon pulmonary angioplasty (BPA), the prognosis of CTEPH patients has been dramatically improved. However, the pathogenesis of CTEPH is unclear, and the lack of effective early diagnostic methods has become a bottleneck limiting the improvement of clinical diagnosis and treatment. In this paper, we reviewed the current research progress on the pathogenesis of CTEPH to increase the understanding of CTPTH disease.

[Analysis of 1 case of convulsion death caused by large dose of diquat poisoning]

A retrospective analysis of a case of death from sudden convulsions caused by oral high-dose diquat was conducted, and the mechanism and treatment of central damage caused by diquat were investigated to lay the foundation for increasing the success rate of treatment of high-dose diquat poisoning. At the same time, at the same time, our clinical treatment experience has also been accumulated.

[National external quality assessment for molecular detection of severe acute respiratory syndrome coronavirus 2 Delta variant]

Objective: To clarify the impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Delta variant on the performance of existing molecular diagnostic assays, and investigate the detection ability of clinical laboratories across China. Methods: The first nationwide external quality assessment (EQA) for molecular detection of Delta variant was carried out based on the non-infectious phage virus-like particles samples, which were prepared by genetic engineering methods and distributed to 8 488 laboratories nationwide. The EQA panel was composed of three Delta variant samples (7.5×10², 1.5×10³ and 6.0×10³ copies/ml), one non-variant weak positive sample and one negative sample. The percentage of agreement (PA) of Delta variant samples with different concentration, the PA of Delta variant and non-variant samples with 7.5×10² copies/ml, the PA of assays used by more than 100 laboratories for Delta variant samples with different concentration and the PA of Delta variant and non-variant samples with 7.5×10² copies/ml were calculated and analyzed. Results: The data from 8 127 laboratories were available for evaluation. The testing capability of 98.77% (8 027/8 127) of the participating laboratories was found to be competent in reporting correct results for all samples. The overall percentage of agreement (OPA), negative percentage of agreement (NPA) and positive percentage of agreement (PPA) of the samples were 99.64% (40 490/40 635), 99.73% (8 105/8 127), 99.62% (32 385/32 508), respectively. With the decrease of the concentration of the samples, the PPA of Delta variant samples decreased. The PPAs were 99.41% and 99.51% for Delta variant and non-variant samples with 7.5×10² copies/ml, respectively, with no statistical difference (P=0.392). The OPA, NPA and PPA of the assays used by more than 100 laboratories were all greater than 98%, and no statistical difference of the PPAs was identified between Delta variant and non-variant samples with 7.5×10² copies/ml (P>0.05). Conclusions: Delta variant fails to impair the performance of current molecular diagnostic assays in China. The clinical laboratories have the same detection capabilities for Delta variant and non-variant samples. However, in certain laboratories, further improvement is required to ensure the accurate detection of weak positive samples.

An atypical primary malignant melanoma arising from the cervical nerve root: A case report and review of literture

BACKGROUND

Primary melanomas affecting the central nervous system are very rare, and melanomas originating in the spinal canal or origin of the spinal nerve root are even rarer. As a consequence, not much is known about this.

CASE SUMMARY

Here we report a case of primary malignant melanoma originating in the cervical spinal cord nerve root. A 64-year-old woman presented with symptoms of numbness in the right side of the neck, pain, and hypoesthesia in the right upper limb which persisted for 1 year. Neurological examination showed that the superficial sensation in the right upper limb had decreased with muscle strength of grade 4. Magnetic resonance imaging examination revealed a mass (approximately 2.5 cm × 1.4 cm × 1 cm) in the right side of the spinal canal in the C-2 plane. Based on findings obtained during operation, perioperative examination, pathological diagnosis, and the diagnostic criteria of primary central melanoma proposed by Hayward, the mass was confirmed to be a melanoma of intraspinal nerve root origin.

CONCLUSION

This is the first case of primary malignant melanoma originating from cervical spinal cord nerve roots and spread along the inside and outside of the spinal canal. The clinical relevance of this case is discussed to provide new insights into the differential diagnosis of intraspinal tumours. Further studies are needed to better understand the mechanisms driving the growth pattern and development of this type of tumour.

[Clinical characteristics and CYP17A1 gene mutation analysis in patients with 17α-hydroxylase/17, 20-lyase deficiency and testicular tumor]

The 17α-hydroxylase/17, 20-lyase deficiency (17-OHD) is a rare disease. The clinical characteristics and gene mutation of 2 late-diagnosed 17-OHD patients with testicular tumor admitted to our hospital from March 2018 to February 2019 were analyzed retrospectively. The two 17-OHD patients were female (46, XY). Laparoscopic abdominal exploration found undeveloped testicles in grey-yellow or grey-red in the groin and iliac fossa. The testicles were removed and showed malignancy in pathology study. Sequencing of the CYP17A1 gene identified c.1247G>A/c.1427T>C and c.985_987delTACinsAA/c.1306G>A complex heterozygous mutations. Taking together, the possibility of 17-OHD should be considered in patients with hypertension, hypokalemia, adrenal adenomatoid hyperplasia together with 46, XY gonadal dysplasia, so as to make early diagnosis and treatment, and avoid dysplastic testicular turning to malignancy.

[Survey on present status of noise exposure of workers in metal processing industry]

Objective: To investigate the distribution of noise exposure between non-steady state noise and steady-state noise for metal processing workers, which will provide scientific basis for the prevention and treatment of noise hazards in metal processing industry. Methods: The cross-section method was used to investigate the noise exposure of 737 workers from three metal processing industries in Zhejiang Province from October to December 2017. The general demographic information and occupational history were collected by questionnaire. The noise was recorded by individual noise meters, and the noise exposure intensity (equivalent continuous A-weighted noise exposure level normalized to an 8 h-working-day, L(Aeq, 8 h)) and kurtosis were calculated. Results: Workers exposed to noise in the metal processing industry were mainly 18-40 years old (527 workers, 71.51%) , men (570 workers, 77.34%) , and junior high school education background (416 workers, 56.45%) . There were 572 workers (77.61%) with noise exposure intensity (L(Aeq, 8 h)) greater than 85 dB (A) , 558 workers (75.71%) exposed to non-steady state noise (kurtosis ≥4) , and 634 workers (86.02%) with exposure duration less than 8 years. Among the 30 work types investigated, the work types with noise intensity reaching 100% were the stamping, welding and others from a children's car manufacturing factory in Ningbo, operating, chamfering, tapping, and thread rolling from an automobile parts manufacturing factory in Ningbo; The work types with a rate of 100% exposed to non-steady state noise were the grinding from a children's car manufacturing factory in Ningbo, assembling, assembly operating and others from an automobile brake manufacturing factory in Wenzhou, and polishing from an automobile parts manufacturing factory in Ningbo. Conclusion: Metal processing workers have a high rate of over-standard exposed to high noise intensity and a high proportion exposed to non-steady state noise. It is necessary to take sound insulation and noise reduction engineering control, and strengthen personal protection and occupational health management measures to prevent and control the noise hazards.

[Impact of enhanced recovery after surgery strategy on early postoperative quality of recovery in patients undergoing laparoscopic surgery for gynecologic malignancy]

Objective: To investigate the impact of perioperative anesthesia management with enhanced recovery after surgery (ERAS) strategy on postoperative recovery in patients undergoing laparoscopic surgery for gynecologic malignancy. Methods: Ninety patients undergoing laparoscopic surgery for gynecologic malignancies from April 2018 to April 2019,aged 18-65 years,with American Society of Anesthesiologists (ASA) physical status Ⅰ or Ⅱ, were recruited and randomly divided into two groups (n=45) using a random number table:ERAS group (group E) and control group (group C). Patients in group E received general anesthesia combined with transverses abdominis plane block and a series of interventions to optimize anesthetic and perioperative management, while patients in group C were treated with routine anesthesia management. Quality of Recovery-40 questionnaire (QoR-40) was administered to assess the early postoperative quality of recovery on 1 day before surgery, and at 24 and 48h after surgery. C-reactive protein (CRP) before and after the operation were evaluated. The incidence of nausea, vomiting and shivering, the time of first exhaust, ambulation, resumption of normal diet, postoperative hospital stay and complications were recorded. Results: The scores of QoR-40 [M(Q₁, Q₃)] in Group E were 175(171, 179) and 185(183, 189) at 24 h and 48 h after operation, which were higher than those in group C [162(160, 167) and 180(179, 183)] (both P<0.01). The levels of CRP in both group E and group C increased at 24 h and 72 h after operation. Moreover, the extent of increasing level of CRP in group C was much higher than that in group E [(39.8±18.0) mg/L vs (13.4±6.3) mg/L, (16.6±8.6) mg/L vs (6.7±2.5) mg/L] at 24 h and 48 h after operation (both P<0.01). Compared with group C, the numerical rating scale (NRS) for nausea decreased significantly in group E [0(0, 2) vs 3 (0, 5), P<0.01]. Meanwhile, the incidence of vomiting and shivering in group E was lower than that in group C [8.9% (4/45) vs 26.7% (12/45); 11.1% (5/45) vs 31.1% (14/45); both P<0.05]. The time of first exhaust, ambulation and resumption of normal diet in group E was (14±6) h, 6(6, 13) h and 1(1, 2) d, respectively, which was markedly shorter than that in group C [(25±10) h, 21(19, 27) h and 3(2, 3) d] (all P<0.01). Overall, the postoperative length of hospital stay reduced significantly for patients who followed the ERAS protocol [7(5, 11) d vs 10(7, 14) d, P<0.01]. The incidence of postoperative complications was 17.8% (8/45) and 37.8% (17/45) in group E and group C, respectively, with a significant difference (P<0.05). Conclusion: Implementation of ERAS anesthesia management in gynecologic oncology patients undergoing minimally invasive surgery alleviates perioperative discomfort, decreases surgical stress response, and improves the early postoperative quality of recovery.

Adropin inhibits the phenotypic modulation and proliferation of vascular smooth muscle cells during neointimal hyperplasia by activating the AMPK/ACC signaling pathway

In-stent restenosis (ISR) remains an inevitable problem for some patients receiving drug-eluting stent (DES) implantation. Intimal hyperplasia is an important biological cause of ISR. It has been previously reported that adropin is a potentially protective factor in cardiovascular disease. Therefore, the present study investigated the function of adropin in inhibiting smooth muscle cell (SMC) phenotype modulation and proliferation, causing intimal hyperplasia. A total of 56 patients who visited the hospital consecutively (25 with ISR and 31 without ISR), who were followed up between April 2016 and March 2019, 1 year following DES, were analyzed to evaluate the association between in-stent neointimal volume and adropin serum levels. Rat aorta smooth muscle cells (RASMCs) were used to determine the effects of adropin on their phenotypic modulation and proliferation using western blot, MTT, PCR and immunofluorescence analyses. Adropin serum levels in the ISR group were significantly lower than those in the non-ISR group. Furthermore, linear regression analysis revealed that only adropin levels were negatively associated with neointimal volume in both groups. The overall adropin levels of the 56 patients and the percentages of neointimal volume revealed a strong negative association. In vitro, adropin suppressed angiotensin II (Ang II)-induced phenotypic modulation in RASMCs by restoring variations of osteopontin and α-smooth muscle actin. Furthermore, compared with the Ang II group, adropin markedly decreased the percentage of G₂/M-phase cells. Finally, adropin negatively regulated the phenotypic modulation and proliferation of RASMCs via the AMP-activated protein kinase/acetyl-CoA carboxylase (AMPK/ACC) signaling pathway. In conclusion, an independent, negative association was revealed between adropin and intimal hyperplasia; specifically, adropin inhibited the phenotypic modulation and proliferation of RASMCs by activating the AMPK/ACC signaling pathway. Therefore, adropin may be used as a potential predictor and therapeutic target for intimal hyperplasia and ISR.

[Diagnostic value of diffusion-weighted imaging and conventional magnetic resonance imaging in testicular tumor]

Apparent diffusion coefficient(ADC) of magnetic resonance imaging≤0.90×10^-3 mm²/s and T2-hypointensity, intratuminal septa, and peritumoral infiltration could achieve best diagnostic efficiency. ADC values and cyst or necrosis were independent predictors for the differential diagnosis of nonseminomatous germ cell tumor versus seminoma and nonseminomatous germ cell tumor versus lymphoma. ADC value and intratuminal septa were independent predictors for the differential of seminoma versus lymphoma.

Numerical study of hydrodynamic characteristics in a moving bed biofilm reactor

The moving bed biofilm reactor (MBBR) has certain advantages, such as high wastewater treatment efficiency, low maintenance and operating costs, and simple operation. It has emerged as a valuable option for small decentralized facilities. The filling ratio, aeration mode and aeration intensity are the main factors that affect the performance of MBBRs in wastewater treatment. However, the information that concerns the used criteria that pertain to the process design for the MBBR is not adequate. In this study, a three dimensional computational fluid dynamics (CFD) model was constructed and the maximum error was only 1.98%, which was much smaller than the traditional 2D-CFD model. The filling ratio, aeration mode and aeration intensity of MBBR were optimized by CFD model from the point of view of fluid mechanics. The results show that the fluidization performance of the filling is the best under the one-side aeration mode with 30% filling ratio. The cost-performance ratio of the reactor with 30% filling ratio was 1.53, 25% and 35% filling ratio were only 1.17 and 1.14 respectively. Increasing the aeration intensity could improve the fluidization performance. However, the effect of high aeration intensity on the fluidization performance of the carrier was limited and the energy consumption increased greatly. The results revealed that when the aeration intensity increased from 0.07 min^-1 to 0.13 min^-1, the proportion of the carrier area increased by 16.56%. The proportion of the carrier area with an aeration rate of 0.20 min^-1 was only 4.23%, which is higher than 0.13 min^-1. The main factors that control the fluidization of the carrier were the range of the flow zone and the flow velocity of the liquid. Increasing the range of the flow zone could facilitate the flow of the carriers. The critical value of the flow velocity of the liquid in the flow zone was 0.04 m/s. These results could guide the optimization design of the filling ratio and the aeration conditions and provide a theoretical basis for the application of MBBR.

[Detection of neuron-specific enolase in patients with subacute 1, 2-dichloroethane poisoning]

Objective: To investigate the changes of neuron-specific enolase (NSE) in serum and cerebrospinal fluid of patients with subacute 1, 2-dichloroethane (DCE) poisoning. Methods: Ten patients with subacute 1, 2-DCE poisoning hospitalized in Guangzhou 12th Municipal People's Hospital from December 2014 to March 2019 were taken as the subacute 1, 2-DCE poisoning group, 34 typical acute toxic encephalopathy patients hospitalized at the same time as typical acute toxic encephalopathy group, 40 healthy physical examinees as normal control group. The levels of serum NSE in patients of subacute 1, 2-DCE poisoning and typical acute toxic encephalopathy group during onset and improvement were detected by chemiluminescence method, and the results were analyzed statistically. The level of NSE in cerebrospinal fluid of subacute 1, 2-DCE poisoning group was detected and analyzed its correlation with the level of NSE in serum. Using receiver operator characteristic (ROC) curve to analyze the diagnostic efficacy of NSE in subacute 1, 2-DCE poisoning and typical acute toxic encephalopathy (area under curve, AUC) . Results: There was no significant difference between the serum NSE level of the patients with subacute 1, 2-DCE poisoning in the onset group and the normal control group and the improvement group (P>0.05) . The serum NSE level of subacute 1, 2-DCE poisoning in the improvement group was lower than those in the normal control group (P<0.01) . The serum NSE level of the subacute 1, 2-DCE poisoning in the onset group was lower than those in the typical acute toxic encephalopathy in the onset group (P<0.01) . There was no linear correlation between cerebrospinal fluid NSE and serum NSE in patients with subacute 1, 2-DCE poisoning (r=-0.183, P=0.52) . ROC curve showed that the AUC of serum NSE in diagnosing subacute 1, 2-DCE poisoning and typical acute toxic encephalopathy were 0.661 and 0.726, respectively. Conclusion: There is no significant change in serum NSE in patients with subacute 1, 2-DCE poisoning.

[A 5-year follow-up study of pneumoconiosis patients with positive autoantibody]

Objective: To explore the progress of small shadow and the change of lung function in pneumoconiosis with positive autoantibody, so as to provide basis for clinical treatment of pneumoconiosis. Methods: A total of 756 patients were admitted to the pneumoconiosis department of the Guangzhou Occupational Disease Prevention Hospital from January 1, 2013 to June 1, 2019. The patients with combined infection were excluded. According to whether the autoantibody was positive, they were divided into positive group and negative group, 25 cases in each group. Follow-up observation of X-ray chest radiographs, chest CT, forced expiratory volume in one second (FEV(1)) and forced expired flow at 50% of FVC (MEF(50)) of pneumoconiosis patients for 5 years, to analyze the influence of positive autoantibody on the morphology of X-ray chest film, the pneumoconiosis promotion in 5 years and lung function. Results: There were 22 males and 3 females in the autoantibody positive group, aged 53.14±10.51 years. In the autoantibody negative group, there were 23 males and 2 females, aged 53.88±8.10 years. During the 5-year observation period, there was no significant difference of small shadow shape, pneumoconiosis stage, and the pneumoconiosis promotion in 5 years between the autoantibody positive group and the autoantibody negative group (P>0.05). However, the increment of small shadow area in the autoantibody positive group was higher than that in the autoantibody negative group (P<0.05). FEV(1) and MEF(50) of the autoantibody positive group were significantly lower than those of the autoantibody negative group in the fourth and third years, respectively (P<0.05). Positive autoantibody was negatively correlated with FEV(1) and MEF(50) (P<0.05). Conclusion: The positive autoantibody can't promote the progress of X-ray, but show more small shadows on chest CT; the positive autoantibody may aggravate the decline of lung function.

Search for an Invisibly Decaying Z^{'} Boson at Belle II in e^{+}e^{-}→μ^{+}μ^{-}(e^{±}μ^{∓}) Plus Missing Energy Final States

Theories beyond the standard model often predict the existence of an additional neutral boson, the Z^{'}. Using data collected by the Belle II experiment during 2018 at the SuperKEKB collider, we perform the first searches for the invisible decay of a Z^{'} in the process e^{+}e^{-}→μ^{+}μ^{-}Z^{'} and of a lepton-flavor-violating Z^{'} in e^{+}e^{-}→e^{±}μ^{∓}Z^{'}. We do not find any excess of events and set 90% credibility level upper limits on the cross sections of these processes. We translate the former, in the framework of an L_{μ}-L_{τ} theory, into upper limits on the Z^{'} coupling constant at the level of 5×10^{-2}-1 for M_{Z^{'}}≤6  GeV/c^{2}.

A Study Based on the Correlation Between Slit2/Robo1 Signaling Pathway Proteins and Polymyositis/Dermatomyositis

AIMS

To investigate the role of Slit2 and Robo1 during the vascular disease of Polymyositis (PM) / dermatomyositis (DM).

BACKGROUND

PM and DM are nonsuppurative inflammatory myopathies that mainly invade the skeletal muscles.

OBJECTIVE

This study attempted to explore the specific mechanism of Slit2/Robo1 signaling pathway proteins during the vascular disease of PM/DM.

METHODS

The mRNA expressions of Slit2 and Robo1 in the muscle tissue were detected by RT-qPCR between newly-diagnosed PM/DM patients and healthy controls. The number of Slit2 and Robo1 positive cells in the serial sections of muscle paraffin tissues was measured by immunohistochemistry in 10 patients with PM, 10 patients with DM and 20 healthy controls.

RESULTS

The study results revealed that the mRNA expressions of Slit2 and Robo1 in muscle tissue in the PM and DM groups were higher than that in the control group (P<0.05). The positive expression rates of Slit2 and Robo1 in muscle tissue in the PM and DM groups were 80.0%, 80.0%, 70.0% and 70.0%, respectively. The difference was statistically significant (P<0.001), when compared to the control group (the positive expression rates were 0% and 10%, respectively).

CONCLUSION

The activation of the Slit2/Robo1 signaling pathway is an important mechanism leading to the development of PM/DM.

[Analysis of 18 cases of toxic encephalopathy caused by occupational acute 1, 2-dichloroethane poisoning]

Retrospective analysis of 18 cases of occupational acute 1, 2-dichloroethane (1, 2-DCE) poisoning. The results showed that all patients have the main manifestations such as dizziness, headache, unresponsiveness and other symptoms of nervous system damage; Brain CT showed varying degrees of diffuse white matter lesions. Brain MRI showed extensive involvement of white matter in both cerebral hemispheres. Affected white matter area presented low intensity on T1WI, hyperintensity on T2WI and T2-Flair; Lumbar puncture examination of cerebrospinal fluid (CSF) pressure (262.5±48.39) mm H(2)O; After treatment, the required time for CSF pressure to restore was (161.56±75.27) days (50-280) days. Summary, Occupational acute 1, 2-DCE poisoning caused by toxic encephalopathy can be manifested as persistent abnormalities in CSF pressure, and the CSF pressure drops slowly during treatment; Early head CT and lumbar puncture examination will be helpful for early detection of intracranial pressure in toxic encephalopathy caused by acute 1, 2-DCE poisoning. Dynamic monitoring of CSF provides guidance for acute 1, 2-DCE poisoning with a long time of treatment and various types of dehydrating agents.

[Correlation of capillary plexus with visual acuity in idiopathic macular epiretinal membrane eyes using optical coherence tomography angiography]

Objective: To observe changes in foveal avascular zone(FAZ) and capillary plexus in idiopathic macular epiretinal membrane (IMEM) in optical coherence tomography angiography (OCTA) and analyze their correlation with the visual acuity. Methods: Cross-sectional study. 42 patients (15 Males and 27 females, age 64.8) from the Eye Hospital of Wenzhou Medical University were included with 51 eyes diagnosed as IMEM (IMEM group), and 23 normal eyes (9 Males and 14 females, control group). All patients received the examination of fissure lamp combined with fundus pre-set lens, best corrected visual acuity (BCVA), OCT angiography (OCTA) and fundus photo. OCTA was performed on 3 mm× 3 mm sections centred on the fovea. The software automatically measured the superficial capillary plexus (SCP) and deep capillary plexus (DCP) vessel density(VD) and retinal thickness(RT) and FAZ area. The IMEM eyes were compared with the normal eyes and correlation between the parameters of OCTA and BCVA was analyzed in IMEM. Independent-sample t test and MannWhitney test were used for comparison between groups, and Spearman test was used for correlation analysis. Results: LogMAR BCVA in the IMEM group was 0.40(0.15, 0.70), in the control group was 0.10(0.05, 0.22). FAZ area of IMEM group was (0.09±0.05) mm(2), while that of control group was (0.34±0.13)mm(2).Compared with the control group, in IMEM group, the BCVA was worse (Z=-4.443, P<0.001), FAZ area was smaller (t=-9.198, P<0.001), RT was increased (P<0.001), The foveal DCP and SCP vessel density was increased (t=4.280, 9.079, P<0.01), The parafoveal DCP vessel density was decreased (P<0.05), The parafoveal SCP vessel density was decreased in superior, inferior and nasal side (t=-2.759, Z=-3.998, Z=-2.108; P<0.05). The BCVA was negatively correlated with FAZ area (r=-0.337, P=0.017), positively correlated with center macular thickness (r=0.324, P=0.020). The BCVA was no correlated with foveal VD and parafoveal DCP vessel density (P>0.05), but correlated with SCP vessel density(P<0.05). Conclusions: In the IMEM eyes the BCVA was worse, FAZ area was smaller, foveal vessel density was increased and the parafoveal vessel density was decreased compared with the normal eyes. The smaller the FAZ area, the smaller foveal SCP vessel density, the poorer BCVA. There was no correlation between BCVA and DCP vessel density. Changes in VD in IMEM eyes may lead to changes in vision. (Chin J Ophthalmol, 2019, 55:757-762).

Scale-Dependent Waylaying Effect of Pollinators and Pollination of Mass-Flowering Plants

Pollinators foraging for food resources can be waylaid by mass-flowering plants located in their foraging pathway in landscapes. The waylaying effect of pollinators is often studied at a single spatial scale; to date, little is known about the best spatial extent at which waylaying effect of pollinators can be measured. In this study, we selected a landscape with mass-flowering tufted vetches to determine the spatial scale of waylaying effect of honey bees as well as the consequence of waylaying effect on vetch pollination service. The spatial scale of waylaying effect was determined by the strongest association between honey bee density and distance, selected from a gradient of nested circular buffers centering on apiaries in three different locations. Linear models were used to predict the influence of flower visitor densities on pollination service. For our landscape, honey bee densities were best associated with distances at spatial scales of 500 m, 1150 m, and 1400 m respectively for the three locations of apiaries. Honey bee was the only pollinator whose density displayed a positive relationship with pollination service. At the scales of effect, honey bee density and pollination service declined along the distance. Our findings suggest that the waylaying effect of pollinators needs to be examined at a specific spatial scale and farmers who use honey bees to pollinate their mass-flowering crops need to consider the spatial scale of waylaying effect of pollinators in order to maximize pollination service within agricultural ecosystems.