Probing CP symmetry and weak phases with entangled double-strange baryons

Though immensely successful, the standard model of particle physics does not offer any explanation as to why our Universe contains so much more matter than antimatter. A key to a dynamically generated matter-antimatter asymmetry is the existence of processes that violate the combined charge conjugation and parity (CP) symmetry1. As such, precision tests of CP symmetry may be used to search for physics beyond the standard model. However, hadrons decay through an interplay of strong and weak processes, quantified in terms of relative phases between the amplitudes. Although previous experiments constructed CP observables that depend on both strong and weak phases, we present an approach where sequential two-body decays of entangled multi-strange baryon-antibaryon pairs provide a separation between these phases. Our method, exploiting spin entanglement between the double-strange Ξ- baryon and its antiparticle2 [Formula: see text], has enabled a direct determination of the weak-phase difference, (ξP - ξS) = (1.2 ± 3.4 ± 0.8) × 10-2 rad. Furthermore, three independent CP observables can be constructed from our measured parameters. The precision in the estimated parameters for a given data sample size is several orders of magnitude greater than achieved with previous methods3. Finally, we provide an independent measurement of the recently debated Λ decay parameter αΛ (refs. 4,5). The [Formula: see text] asymmetry is in agreement with and compatible in precision to the most precise previous measurement4.

An audit of trauma laparotomy in children and adolescents highlights the role of damage control surgery and the need for a trauma systems approach to injury in this vulnerable population

BACKGROUND

This study reviews the indications and outcome of emergency laparotomy for paediatric trauma in a South African trauma centre.

METHODS

This was a retrospective study of all children less than 18 years of age who underwent an emergency laparotomy for trauma between December 2012 and October 2020 at Grey's Hospital in Pietermaritzburg.

RESULTS

During the eight-year period under review, a total of 136 children of which 107 were male underwent a laparotomy for trauma. The median age was 14 years. There were 80 (57.1%) blunt mechanisms, and the rest were penetrating mechanisms. A total of 46 (33%) patients required ICU admission. Thirty-four patients developed a complication. These included nine cases of pneumonia, one case of renal failure, two patients developed abdominal collections, three woundrelated complications, three neurological complications and one miscellaneous complication. There were seven (5%) deaths. The penetrating cohort were older than the blunt cohort. Solid viscera were more likely to be injured in the blunt cohort and hollow viscera more likely in the penetrating cohort. A total of 16 (11%) patients underwent damage control surgery (DCS). Of this cohort, there were three female children. Six sustained blunt trauma and ten penetrating trauma. A total of six (37%) of these children died.

CONCLUSION

Emergency laparotomy for trauma in children is not infrequent in Pietermaritzburg and there is a high incidence of penetrating trauma in this cohort. The response to increased degrees of physiological derangement is the application of DCS. Ongoing efforts to develop and strengthen a paediatric trauma service appear to be justified.

[All-inside subtalar arthroscopy through three portals combined with rafting screws technique for the treatment of the calcaneal fractures of Sanders Ⅱ and Ⅲ]

Objective: To investigate the surgical technology and clinical efficacy of using the all-inside subtalar arthroscopy through three portals combined with rafting screws technique for the treatment of the calcaneal fractures of Sanders Ⅱ and Ⅲ. Methods: The clinical data of 33 patients (33 feet) with intra-articular displaced calcaneal fractures treated by modified all-inside arthroscopic from March 2017 to March 2019 at Department of Orthopedics,Xuzhou Central Hospital were retrospectively analyzed.There were 19 male patients,and 14 female patients,aged (32.6±11.3) years(range:20 to 55 years). According to the Sanders classification,there were 12 cases of type Ⅱ and 21 cases of type Ⅲ. The duration from injury to surgery was (101.2±32.1) hours(range:6 to 140 hours).The preoperative visual analogue scale (VAS) was 6.4±2.9 (range: 4 to 8); The preoperative American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot scale and the SF-36 score was 63.3±11.8 (range:50 to 75) and 94.8±9.1 (range:70 to 105) respectively.All the patients were managed with the all-side subtalar arthroscopy through three portals combined with rafting screws technique.The incision healing,reduction of fracture,and fracture healing were recorded.The VAS,AOFAS ankle-hindfoot scale,and SF-36 score were used to assess the pain and functional outcomes.Repeated-measurement was used to compare the scores before and after surgery. Results: The time of operation was (69.7±10.4) minutes (range:40 to 110 minutes). All patients did not undergo bone grafting.The incision healed in one stage without complications of skin sensory and peroneal tendon injury.All patients were followed up for 24 months.At the last follow-up,all the patients were satisfied with the hindfoot alignment,function,and hindfoot appearance.Postoperative calcaneal imaging indicators (calcaneal length,calcaneal width,calcaneal height,Bohler angle and Gissane angle) were significantly improved compared with those before surgery (P<0.01).There was no statistically significant difference in the imaging indexes of calcaneus at 1 day,1 year and 2 years after surgery,indicating no loss of fracture reduction (all P>0.05).The VAS,AOFAS ankle-hindfoot scale,and SF-36 score were 1.5±0.4 (range: 0 to 2),94.0±6.5 (range:90 to 100),and 119.1±7.2 (range:105 to 130),respectively,which were better than those before surgery (all P>0.05).According to the AOFAS scoring system,27 cases were excellent,4 cases were good, 2 cases were fair,and the excellent and good rate was 94.0%. Conclusion: All-inside subtalar arthroscopy through three portals combined with rafting screws technique for the treatment of the calcaneal fractures of Sanders Ⅱ and Ⅲ provides precise reduction,reliable fixation,satisfactory function and limited complications,which is an alternative method.

[A nationalsurveyandresults analysisof seizure prophylaxis after aneurismal subarachnoid hemorrhage]

Investigate theclinical practice of seizure prophylaxis after aneurysmal subarachnoid hemorrhage in Chinese neurosurgeons.Aquestionnaire for this theme was designed and was sent to respondents through the internet.From July 2021 to October 2021, atotal of forty-three eligible questionnaires were collected. All responders come from affiliated hospitals of medical schools in China. Each of these hospitals admitted more than one hundred patients with aneurysmal subarachnoid hemorrhage per year. Only 9.3% (4/43) of responders disagree with the prophylactic use of anticonvulsants. 86.04% (37/43) of responders perform seizure prophylaxis in clinical practice. Sodium valproate is the most commonly used regimen; 94.59% (35/37) of responders who perform prophylaxis chose this drug. The medication period differs sharply fromlessthan 3 daystolongerthan 14 daysamong different hospitals. The use of EEG was insufficient in Chinese patients. A low seizure rate was reported according to the feedback from Chinese neurosurgeons.In China, seizure prophylaxis after subarachnoid hemorrhage was not yet standardized. Clinicians' mastery of relevant knowledge is still not enough. Carrying out high-quality clinical research can help justify the use of anticonvulsants, which could also positively impact rational drug use.

[The ineffective or short-term recurrence of trigeminal neuralgia after microballoon compression:different causes and management strategies]

Objectives: To explore the causes of ineffective or short-term recurrence (within 3 months)of trigeminal neuralgia treated by percutaneous microballoon compression(PBC), and to examine the reoperative strategies and clincal outcomes of modified PBC. Methods: The clinical data of 21 patients with ineffective or short-term recurrence after PBC treatment (5.7% of 369 patient received PBC) admitted to the Department of Neurosurgery,Nanjing Drum Tower Hospital Clinical College of Nanjing Medical University from June 2018 to June 2020 were retrospectively analyzed.There were 8 males and 13 females, mean aged 66.6 years (range:51 to 79 years).Among them,2 patients was ineffective after PBC and 19 patients relapsed within 3 months.The distribution of pain was along V₂ branches in 2 cases,V₃ branches in 3 cases,V₁+V₂ branches in 1 case,and V₂+V₃ branches in 15 cases.The mean time of recurrence was 46.8 days (range:23 to 76 days) among the 19 patients with short-term recurrence.The patients were divided into 4 types based on the causes of postoperative ineffectiveness or short-term recurrence.TypeⅠ:extracapsular false pear (1 case);Type Ⅱ:invalid true pear(2 cases);Type Ⅲ:capsular rupture (6 cases);Type Ⅳ:compression blind area (12 cases).The individualized modified PBC operation plans were used according to the types of the patients and the clinical effect and complications of the patients were observed. Results: The pain symptoms of the patients disappeared after the second operation with immediate effective rate of 100%. All patients had mild facial numbness after surgery.Five patients(23.8%,5/21) had masseter muscle weakness, 3 (14.3%,3/21) had peristomatous herpes, 1(4.8%, 1/21) had diplopia.No bleeding or other complications occurred.All patients were followed up for at least 12 months (range:13 to 28 months). One patient (4.8%,1/21) (compression blind area type) had pain recurrence 9 months after surgery, and cured by receiving the original modified PBC surgery again with no recurrence after another 13 months' follow-up. None of the other patients relapsed during the follow-up period.Up to the last follow-up,19 cases(90.5%,19/21) were cured,and 2 cases (9.5%,2/21) were relieved. Conclusions: The main reason for ineffective or short-term recurrence of PBC in trigeminal neuralgia patients is the ineffectively compressed of trigeminal ganglion.According to the different types of patients,the use of individualized modified surgical scheme can improve the efficacy of PBC surgery.

[Impacts of glycemic variability on the relationship between time in range and estimated glycated hemoglobin in patients with type 1 diabetes mellitus]

Objective: This study is to investigate the relationship between time in range (TIR) and glucose management indicator (GMI), and the impact of glycemic variability (GV) on their relationship in patients with type 1 diabetes mellitus (T1DM). Methods: The CGM data were collected from a multicenter randomized clinical trial of adults (≥18 years old) with T1DM, including 83 T1DM patients, respectively from the Third Affiliated Hospital of Sun Yat-sen University (72 cases), Drum Tower Hospital Affiliated to Nanjing University School of Medicine (2 cases), and the First Affiliated Hospital of University of Science and Technology of China (9 cases). All subjects wore the iPro^TM2 system for 14 days at baseline (0-2 weeks), 3 months (12-14 weeks), and 6 months (24-26 weeks). Data derived from iPro^TM2 sensor was used to calculate CGM parameters. Correlation between TIR and GMI was explored according to different stratification of glycemic variability assessed by glucose coefficient of variation (CV). Predicted TIR in the fixed GMI value was calculated via the linear regression equations performed in the respective interquartile group of CV. Results: From November 2017 to June 2021, a total of 233 CGM data were collected with 83 collected from baseline, 80 from the 3-month follow-up, 70 from the 6-month follow-up. Patients including 27 males had a median (Q₁, Q₃) age of 30.69 (25.22, 38.43) years, with a diabetes duration of 10.05(4.46, 13.92) years. The median (Q₁, Q₃) and effective wearing time of available CGM data was 13.92 (13.02, 14.00) days and 91.61% (84.96%, 95.94%), and the value of TIR, GMI and CV was 60.34%±13.03%, 7.14%±0.61% and 41.01%±7.64%, respectively. There was a strong negative correlation between TIR and GMI (r=-0.822, P<0.001). Multiple linear regression analysis showed that the predictive value of TIR calculated from a given GMI was 8.352% higher when CV was up to standard (36%) than that when CV was down to standard. Based on the multiple linear regression equations generated from quartiles of CV, the predicted TIR value was decreased across the ascending quartiles with 69.98 % in the lowest quartile of CV (≤35.91%), 64.57 % in 25^th-50^th quartile of CV (35.91%<CV≤40.08%), 60.96% in 50^th-75^th quartile of CV (40.08%<CV≤45.86%) and 56.44% in the highest quartile of CV (>75^th quartile, CV>45.86%) when GMI was set as 7%. Conclusions: There is a strong correlation between TIR and GMI in adult patients with T1DM in patients with type 1 diabetes mellitus. CV influenced the relationship between TIR and GMI.

[Clinical effect and influencing factors of focused ultrasound ablation surgery combined with suction curettage for the treatment of mass-type cesarean scar pregnancy]

Objective: To investigate the clinical effect of focused ultrasound ablation surgery (FUAS) combined with suction curettage for mass-type cesarean scar pregnancy (CSP) and to analyze the influencing factors of vaginal bleeding and readmission. Methods: From January 2014 to December 2020, 88 patients with mass-type CSP were treated by FUAS combined with suction curettage in the Third Xiangya Hospital of Central South University. The clinical results and the influencing factors of bleeding and readmission for mass-type CSP were analyzed. Results: All the patients underwent one time FUAS treatment successfully. Immediately after FUAS treatment, color Doppler ultrasound showed obvious necrosis and no perfusion area in all lesions, and the blood flow in the mass-type CSP tissue significantly decreased. The median volume of blood loss in the procedure was 20 ml (range: 5-950 ml). Thirteen patients (15%, 13/88) had vaginal bleeding≥200 ml, and 15 patients (17%, 15/88) were hospitalized again. The average time for menstruation recovery was (28±8) days (range: 18-66 days). The average time needed for serum human chorionic gonadotropin-beta subunit to return to normal levels was (22±6) days (range: 7-59 days). The risk of large vaginal bleeding of patients were related to the blood supply of the mass (OR=5.280, 95%CI: 1.335-20.858, P=0.018) and the largest diameter of the mass (OR=1.060, 95%CI: 1.010-1.120, P=0.030). The risk of readmission were related to the largest diameter of the mass (OR=1.055, 95%CI: 1.005-1.108, P=0.030) and the depth of the uterus cavity (OR=1.583, 95%CI: 1.015-2.471, P=0.043). No serious complications such as intestinal and nerve injury occurred during and after FUAS treatment. Conclusions: FUAS combined with suction curettage is safe and effective in treating patients with mass-type CSP through this preliminary study. The volume of vaginal bleeding are associated with the blood supply of the mass and the largest diameter of the mass, the risk of readmission are related to the largest diameter of the mass and the depth of the uterus cavity.

Observation of the Singly Cabibbo Suppressed Decay Λ_{c}^{+}→nπ^{+}

The singly Cabibbo-suppressed decay Λ_{c}^{+}→nπ^{+} is observed for the first time with a statistical significance of 7.3σ by using 3.9  fb^{-1} of e^{+}e^{-} collision data collected at center-of-mass energies between 4.612 and 4.699 GeV with the BESIII detector at BEPCII. The branching fraction of Λ_{c}^{+}→nπ^{+} is measured to be (6.6±1.2_{stat}±0.4_{syst})×10^{-4}. By taking the upper limit of branching fractions of Λ_{c}^{+}→pπ^{0} from the Belle experiment, the ratio of branching fractions between Λ_{c}^{+}→nπ^{+} and Λ_{c}^{+}→pπ^{0} is calculated to be larger than 7.2 at the 90% confidence level, which disagrees with most predictions of the available phenomenological models. In addition, the branching fractions of the Cabibbo-favored decays Λ_{c}^{+}→Λπ^{+} and Λ_{c}^{+}→Σ^{0}π^{+} are measured to be (1.31±0.08_{stat}±0.05_{syst})×10^{-2} and (1.22±0.08_{stat}±0.07_{syst})×10^{-2}, respectively, which are consistent with previous results.

[Clinical features and prognostic influences of retropharyngeal lymph node metastasis in oropharyngeal and hypopharyngeal squamous cell carcinoma: a meta analysis]

Objective: To compare the clinical features and prognoses of patients with oropharyngeal or hypopharyngeal squamous cell carcinoma (SCC) with and without retropharyngeal lymph node metastases. Methods: PubMed, Cochrane, Web of Science, CNKI, VIP and Wanfang databases were searched for published literatures on retropharyngeal lymph node metastasis of oropharyngeal or hypopharyngeal squamous cell carcinoma (1900, 2021), and outcome indicators such as survival rate and related clinical features were extracted. The quality evaluation of the included literatures was carried out. RevMan 5.4 and Stata 16.0 software were used for data analysis. Results: A total of 18 literatures were included. Meta analysis showed that 3-year and 5-year survival rates and 5-year disease-specific survival rate of patients with oropharyngeal or hypopharyngeal squamous cell carcinoma with retropharyngeal lymph node metastases were lower than those without metastases, 46.1% vs. 53.0%, 40.8% vs. 62.5% and 35.9% vs. 53.1%, respectively, and the differences were statistically significant (OR values were 0.26, 0.38, 0.38, and 95%CI were 0.10-0.69, 0.28-0.51, 0.23-0.65, respectively, all P values<0.05). There were statistically significant differences in clinical stage (III-IV), T stage (T3+T4), N stage (N2), positive cervical lymph node metastases and number of lymph node metastases (≥3) between the two groups (OR values were 4.28, 2.20, 2.88, 10.83, 6.53, and 95%CI were 1.70-10.74, 1.35-3.58, 1.90-4.34, 3.57-32.95, 1.75-24.38, respectively, all P<0.05). The sensitivity and specificity of preoperative imaging for diagnosing retropharyngeal lymph nodes metastases were respectively 0.72 (95%CI=0.54-0.85) and 0.98 (95%CI=0.74-1.00), and the area under curve (AUC) of summary receiver operating characteristic curve (SROC) was 0.84 (95%CI=0.80-0.87). Conclusions: The survival rate of patients with oropharyngeal or hypopharyngeal squamous cell carcinoma with retropharyngeal lymph node metastasis is significantly reduced, the clinical stage and T stage are late, and the cervical lymph node metastasis rate is high. Retropharyngeal lymph node metastasis is more insidious, the sensitivity of preoperative imaging diagnosis is not high.

Leucine Alters Blood Parameters and Regulates Hepatic Protein Synthesis via mTOR Activation in Intrauterine Growth Restriction Piglets

Neonatal piglets often suffer low birth weights and poor growth performance accompanied by the disruption of protein metabolism, when intrauterine growth restriction (IUGR) takes place during pregnancy, leading to a higher mortality and bigger economic loss than expected. Leucine has been proposed to function as a nutritional signal regulating protein synthesis in numerous studies. The aim of this study was to determine the effect of dietary leucine supplementation on the blood parameters and hepatic protein metabolism in IUGR piglets. Weaned piglets were assigned to one of four to treatments in a 2 × 2 factorial arrangement: (1) piglets fed a basal diet with normal birth weight; (2) piglets fed a basal diet plus 0.35% L-leucine with normal birth weight; (3) IUGR piglets fed a basal diet with low birth weight; (4) IUGR piglets fed a basal diet plus 0.35% L-leucine with low birth weight. The results showed that IUGR decreased serum aspartate aminotransferase and alkaline phosphatase activities, increased serum cortisol and prostaglandin E2 levels at 35 days of age (P < 0.05), suggesting the occurrence of liver dysfunction and stress response. Leucine supplementation increased serum alkaline phosphatase activity, and decreased serum cortisol levels at 35 days of age (P < 0.05). IUGR decreased the lysozyme activity and complement 3 level in serum (P < 0.05), which were prevented by dietary leucine supplementation. IUGR piglets showed increased hepatic DNA contents while showing reduced RNA/DNA ratio (P < 0.05). Piglets supplied with leucine had decreased RNA/DNA ratio in the liver (P < 0.05). Leucine supplementation stimulated hepatic protein anabolism through up-regulating protein synthesis related genes expression and activating the phosphorylation of mammalian/mechanistic target of rapamycin (mTOR) (P < 0.05). Moreover, IUGR inhibited the mRNA expression of hepatic protein degradation related genes, indicating a compensatory mechanism for the metabolic response. Dietary leucine supplementation attenuated the suppression of the protein catabolism induced by IUGR in liver. These results demonstrate that dietary leucine supplementation could alter the blood parameters, alleviated the disrupted protein metabolism induced by IUGR via enhanced mTOR phosphorylation to promote protein synthesis in weaned piglets.

Therapeutic Potential of Umbilical Cord MSC in Crohn's Disease Is Related to Regulation of the Relative Content and Function of Th17 Lymphocytes

Inflammatory bowel diseases, including Crohn's disease and ulcerative colitis, are chronic and relapsing autoimmune disorders with active participation of Th17 lymphocytes. In the recent treatment strategy of Crohn's disease, human umbilical cord matrix (Wharton's jelly) has been reported having immune privilege. In this study, primary umbilical cord MSC were isolated and cultured for further treatment, their immunophenotype and functional features were confirmed by flow cytometry and adipogenesis, osteogenesis, and chondrogenesis assays. Peripheral blood mononuclear cells (PBMC) were isolated from 11 patients with fistulizing Crohn's disease and 14 healthy volunteers, and the proportions of CD8-CD17A⁺T lymphocytes and CD3⁺T cells in these samples cultured in the presence or absence of umbilical cord MSC were analyzed by flow cytometry. In addition, proliferation of T cells was assessed by CFSE staining. In PBMC samples from patients with Crohn's disease, the content of CD8-CD17A⁺T lymphocytes was higher than in samples from heathy controls, however, co-culturing with umbilical cord MSC decreased the proportion of CD8-CD17A⁺T lymphocytes in PBMC samples isolated from Crohn's disease patients. Additionally, co-culturing of PBMC from Crohn's disease patients with umbilical cord MSC improved T cells function, including CD3⁺T cells level and T cells proliferation. These results suggest that umbilical cord MSC treatment could alleviate elevation CD8-CD17A⁺T lymphocyte in Crohn's disease patients and modulate T cells dysfunctions, which implies that umbilical cord MSC might be a promising strategy for Crohn's disease patients.

[Changes of coagulation function in patients with adenomyosis]

Objective: To explore the different coagulation state in patients with adenomyosis and its clinical significance. Methods: Clinical data of the patients admitted to the First Affiliated Hospital of Nanjing Medical University from January 2017 to December 2021 were retrospectively analyzed. (1) Differential coagulation state between 25 healthy women and 25 patients with adenomyosis were compared during menstrual and non-menstrual periods. (2) The coagulation indexes of 145 patients with adenomyosis (observation group 1) and 129 patients with cervical intraepithelial neoplasia grade Ⅲ (control group 1) who underwent hysterectomy in non-menstrual period were compared. (3) The coagulation indexes of 154 patients with adenomyosis (observation group 2) and 147 women without myometrial lesions (control group 2) who underwent endometrial curettage during uterine bleeding period were compared. (4) Correlations of coagulation index with cancer antigen 125 (CA₁₂₅), cancer antigen 19-9 (CA_19-9) and uterine volume in patients with adenomyosis were analyzed. Results: (1) The coagulation state of each health women during the menstrual and non-menstrual period showed no significant differences (all P>0.05). For the 25 patients with adenomyosis, fibrinogen [FIB; 2.61 g/L(2.50-3.10 g/L)] and D-dimer [0.60 mg/L (0.40-1.00 mg/L)] in the menstrual period were significantly higher than those in the non-menstrual period [2.25 g/L (1.90-2.70 g/L) and 0.27 mg/L (0.20-0.40 mg/L), respectively; both P<0.01], while thrombin time [TT; 16.70 s (16.10-17.40 s)] in the menstrual period was significantly lower than that in the non-menstrual period [17.95 s (17.20-18.40 s); P<0.01]. (2) In the non-bleeding period, D-dimer [0.26 mg/L (0.20-0.40 mg/L)] and platelet count [257.0×10⁹/L (212.0×10⁹/L-308.5×10⁹/L)] of observation group 1 were significantly higher than those of control group 1 (all P<0.01). Besides, FIB (r=0.237, P=0.004) and D-dimer (r=0.373, P<0.001) were positively correlated with CA₁₂₅, while prothrombin time (PT; r=-0.208, P=0.012) and internationalized normalized ratio of plasma prothrombin time (PT-INR; r=-0.201, P=0.015) were negatively correlated with CA_19-9. (3) In the bleeding period, PT [10.70 s (10.10-11.20 s)] and PT-INR [0.93 (0.90-1.00)] of observation group 2 were significantly lower than those of control group 2 (all P<0.01), while D-dimer [0.41 mg/L (0.20-0.80 mg/L)] was significantly higher than that in the control group 2 (P<0.001). Furthermore, FIB (r=0.252, P=0.038) and D-dimer (r=0.321, P=0.008) were positively correlated with uterine volume, while activated partial thromboplastin time (APTT; r=-0.190, P=0.018) and TT (r=-0.304, P=0.012) were negatively correlated with uterine volume. (4) During non-menstrual period and uterine bleeding period, APTT and TT in patients of observation group 1 and 2 combined with anemia were significantly lower than those of non-anemia patients (all P<0.05). Conclusion: Patients with adenomyosis have a tendency to hypercoagulability in both the uterine bleeding and non-bleeding periods, which may be related to enlarged uterine volume, increased serum CA₁₂₅ and anemia.

α -event characterization and rejection in point-contact HPGe detectors

P-type point contact (PPC) HPGe detectors are a leading technology for rare event searches due to their excellent energy resolution, low thresholds, and multi-site event rejection capabilities. We have characterized a PPC detector's response to α particles incident on the sensitive passivated and p + surfaces, a previously poorly-understood source of background. The detector studied is identical to those in the Majorana Demonstrator experiment, a search for neutrinoless double-beta decay ( 0 ν β β ) in 76 Ge. α decays on most of the passivated surface exhibit significant energy loss due to charge trapping, with waveforms exhibiting a delayed charge recovery (DCR) signature caused by the slow collection of a fraction of the trapped charge. The DCR is found to be complementary to existing methods of α identification, reliably identifying α background events on the passivated surface of the detector. We demonstrate effective rejection of all surface α events (to within statistical uncertainty) with a loss of only 0.2% of bulk events by combining the DCR discriminator with previously-used methods. The DCR discriminator has been used to reduce the background rate in the 0 ν β β region of interest window by an order of magnitude in the Majorana Demonstrator  and will be used in the upcoming LEGEND-200 experiment.